What causes Prop Pox (and how to avoid it)

[catty]

Peg now has the entire catalog at Simpeg productions. You will have to register for the PLEX though. (and BTW I love Terry Pratchett, great sig!)

Its not on the PLEX either, but I did find the old support topic for it started in January 2004

http://www.simpeg.com/forum/index.php?topic=230.0

Changes From Previous Version:
1. This new beach now replaces the original beach in the Parks Menu.
2. This new beach is easier to place than the original beach.

Lot Description:
----------------
Although this replacement for the beach has some visual enhancements over the existing beach, its primary purpose is to eliminate the existing beach which uses a horrendous amount of system resources. If you are experiencing notable performance problems on a fairly adequate or better computer, then the cause is most likely the use of beaches in your cities.

Removing all the beaches will solve your performance problem. Replacing them with this new beach will keep your cities looking spiffy... and give the area a slightly improved YIMBY as well.

This new beach is easier to place than the original beach. It will tolerate a slightly greater degree of slope and is more flexible concerning its placement along the shore. This new feature should make replacing existing beaches easier as they where prone to alter the terrain when placed, prohibiting replacement..

Plop costs and monthly maintenance fees have been increased slightly... as has the park effect. The beach also now draws a bit of electricity to power the lights. All these modifications are very minimal.

Special Things to look for:
1. A film crew may occasionally show up to film their lead story for the five o'clock news.

and this from May 2004

My material is currently unavailable as it is being updated for release on the new exchange. Older lots are being transit enabled, props and textures updated, etc... I have been working on the beaches attempting to rid them of the water graphic bug... with little success so far I'm afraid.

I can't find any information on when it was released after this date and what changes were made to it, but it must have been as I know I downloaded it from the STEX sometime in 2007

[MandelSoft]

Guess what: my most populated city I've ever made is now affected by the Prop Pox, just when I decided to make an update for my MD . I used Z's method to restore the city's props (which actually didn't restore my T21s), and all traffic suddenly drops to zero (I believe other people have ran into this problem too), reducing my city's population from 675K to only 389K. Fortunately I have backed-up my Poxed city, in case something went wrong, like this...

The oddest thing is I have at least two cities with filesizes larger than 30 MB that don't have the Prop Pox. It's the first time it occured to me and I hope it will be the last time...

EDIT: I might have an idea which prop caused the prop pox to appear, since I didn't used it in my city before. Before it occured, my city save-file was way over 16MB without any problems. Now it suddenly appears. This may be the only way to un-infect the city...

Best,
Maarten

[MandelSoft]

Sorry for the double-post, but I have some great news: I've succeed to completely UNDO the Prop Pox! What did I do:

- I opened the city affected by the Prop Pox while having the city details set to low.
- I demolished the LOTs with the props causing the Prop Pox to appear initially. (This is the most important step). In my case, it was one set of my experimental ploppable median lights that caused the problem.
- I saved the city and exit to region.
- I changed the city detail settings to high again.
- And guess what: the Prop Pox vanished! And I'm happy again 

Best,
Maarten

[RippleJet]

EDIT: I might have an idea which prop caused the prop pox to appear, since I didn't used it in my city before. Before it occured, my city save-file was way over 16MB without any problems. Now it suddenly appears. This may be the only way to un-infect the city...

It's not the city save file that needs to be over 16 MB, it's the prop subfile within that file.
And that file you can only see by Reader or Wouanagaine's SC4 Savegame Explorer.

- I demolished the LOTs with the props causing the Prop Pox to appear initially. (This is the most important step). In my case, it was one set of my experimental ploppable median lights that caused the problem.

What did you do in those experimental lights?

- And guess what: the Prop Pox vanished! And I'm happy again 

I certainly hope so, Maarten. Let us know what happens in he future when you keep playing that city.

[MandelSoft]

It's not the city save file that needs to be over 16 MB, it's the prop subfile within that file.
And that file you can only see by Reader or Wouanagaine's SC4 Savegame Explorer.

Well, when your file size drops from 60MB to only 15MB, then there must be something wrong.

By the way, there may be something about the 16MB filesize 'limit'. 16MB is exactly 2²⁴ bytes, and therefore 2³² bits. Since most current systems are 32 bit, it may have to do with allocation. But this is just a wild guess 

What did you do in those experimental lights?

Nothing out of the ordinary to me. But maybe I did something wrong, because all other 13 sets don't cause any problems. I'll check the prop descriptiors again for error...

I certainly hope so, Maarten. Let us know what happens in he future when you keep playing that city.

I'll sure do. At the moment, it seems that my problem's solved, and all my props (a significant ammount, since it affected about ¹/₆ of all my props on the map) are back.

Best,
Maarten

[RickD]

I got the Prop Pox again.

Infected city:


Pox-free backup from a month ago:


Isn't there something odd?
A month ago: not compressed, Pox free
now: compressed, poxed

[RippleJet]

Isn't there something odd?
A month ago: not compressed, Pox free
now: compressed, poxed

Not really anything odd with that... (unfortunately)

When your city grows, lower stage lots are replaced by higher stage lots.
Lower stage lots are those which contain the largest number of props (per tile).
Thus, when you city grows upwards (and not horizontally), the number of props actually drops.

And, as you can see, the uncompressed size of the prop subfile is now just under 16 MB.
Any time the size of the prop subfile is under 16 MB, it will be compressed.

And, as we've seen the prop pox may appear whenever that limits is crossed
(probably regardless whether the size goes from below to above 16 MB or v/v).
All depending on whether one of the known props was erased during that crossing of the limit.

[RickD]

That makes sense. But does that also mean that my city (the backup) will be safe as long as I keep the number of props high?

I retraced what I did to my plugin folder in the past weeks and the only big thing I did was removing some street mods (Jeronij's or SFBT street side mod, Peg's Avenue Mod, the Light Replacement Mod). When I run the city without doing anything it will be pox free (at least for a few years). But as soon as I use the road tools and click on existing roads (thus probably deleting the props of the removed mods?) the pox break out.
When I put the mods back in and click on the roads: no pox. But I have not done any long term testing yet. Only let the city run for a few game years.

I am sure I removed the known props when I started this tile from scratch. Maybe one of them got back in somehow.

[Terring7]

Sorry for the double-post, but I have some great news: I've succeed to completely UNDO the Prop Pox! What did I do:

- I opened the city affected by the Prop Pox while having the city details set to low.
- I demolished the LOTs with the props causing the Prop Pox to appear initially. (This is the most important step). In my case, it was one set of my experimental ploppable median lights that caused the problem.
- I saved the city and exit to region.
- I changed the city detail settings to high again.
- And guess what: the Prop Pox vanished! And I'm happy again 

Best,
Maarten

So you found the cure? Congrats!!

[j-dub]

I demolished the LOTs with the props causing the Prop Pox to appear initially.

Good for you, but personally for others, it seems like anyone figuring what the Lots are that initially cause this seems challenging. However though, I must you for defeating the deadly pox.

[RippleJet]

- I demolished the LOTs with the props causing the Prop Pox to appear initially. (This is the most important step). In my case, it was one set of my experimental ploppable median lights that caused the problem.

I retraced what I did to my plugin folder in the past weeks and the only big thing I did was removing some street mods (Jeronij's or SFBT street side mod, Peg's Avenue Mod, the Light Replacement Mod). When I run the city without doing anything it will be pox free (at least for a few years). But as soon as I use the road tools and click on existing roads (thus probably deleting the props of the removed mods?) the pox break out.
When I put the mods back in and click on the roads: no pox. But I have not done any long term testing yet. Only let the city run for a few game years.

Is there a connection here, or am I just trying to make one?

[vil]

I was just about to ask.. Just downloaded the LRM a few minutes ago and there is a bunch of changed rkt4 exemplars with old Maxis IDs in there...

[cowcorn]

Hi all!

I have a question :

Several of my cities from my old region are infected. I am ready to rebuild a few of them from scratch but I would like to keep the terraforming I did on the tiles. Would using the "Obliterate city" function clean the save files and prevent reappearance of the prop pox provided that I cleaned my pluggins of any problematic files?

Joel

[MandelSoft]

^ "Obliterate city" would do the job, at least in my experience.

I was just about to ask.. Just downloaded the LRM a few minutes ago and there is a bunch of changed rkt4 exemplars with old Maxis IDs in there...

Only one particular set caused problems, but the other sets don't cause any problems.

I have to say that my solution only solves one quite easy to track problem. There probalbly multiple, complex causes for the Prop Pox. I just got the luck that mine was very easy to solve...

[GMT]

so since new posts popped up since I started editing my previous post, I deleted it and post anew here.

disregard the previous post of mine.
looks like I was a little too fast at reading this thread.
now, I stand corrected, posting my "newer" thoughts.
from 95 more or less developed city tiles all under the same plugin setup (as I sort them by necessity for the used region), 1 is infected and 2 others are poxed. everything else is pox free per bap's definition a few pages back. Development is suburban sprawl style with LOADS of low density buildings, about 90% the huston style medium wealth to precisize it, needless to say I am literally splattered with props so crossing the 16mb threshold is mandatory rather than optional in many cases.
curious tho, the region was started prior to my findings of what prop pox is, thus prior to what bap does suggest to alter in terms of peg's files, but definitely they were on board. A rough estimation is this region is 3-4 years old, my learning of bap's findings occured much later.
so basically this would mean that I am bound to be poxed sooner rather than later.
As I learned from the previous pages, sc4 save is considered a sureshot in terms of identifying the 3 states of pox free, infected and poxed, that's why I ran all cities through it, one by one.
What lead me even further into confusion, as one of the poxed cities is available in a backup file which is according to sc4save, not poxed and not infected (namely 0 disabled props, no poxed warning). the prop file is well beyond 16mb in this "clean" version.
So both the infection and the outbreak must have happened later on. Only changes to it tho are as recent as within the last fortnight, when I demolished quite some parts and the prop file dropped well below 16mb. I guess same accounts for the other poxed city, I did some minor changes but have lots of midrise buildings, many of which are grown C$$, so there was in fact a growth circle as explained earlier. As the prop file is just below 16mb, I guess once more the reason is in crossing the threshold backwards, keeping in mind that other cities positively crossed the threshold and stand unaffected according to sc4 save.
Cross searching the web led my to simforum.de where diggis is cited with a probable solution similar to the one Z named here.
I tried this and the prop files in both poxed cities doubled in uncompressed size, thus positively crossing the 16mb threshold again. Still poxed according to sc4 save tho, but at least for one saving process, all props remained visible.
This got me back at the beginning of not knowing anything as it pretty much contradicts my previous findings, albeit they are not wrong either.
a quick resumé wont hurt here, stating the relevant points:

• according to bap's findings, my beloved region WILL attract the pox, since editing out his findings happened after starting the region.
• one poxed city is available in a completely clean state beyond the 16mb threshold
• same city became both infected and poxed within the last fortnight, allegedly by negatively crossing the 16mb threshold

I did some further investigating, leading me even further into confusion, as I gave the virus detector thingy a shot and came up with my entire region being splattered with the affected props (no big deal testing, know the state of one, know the state of all as all the same tilesets, thus same buildings all over the place... like I said, suburban sprawl). Now keeping in mind previous findings, once more I wonder why most cities, holding the named props, being beyond 16mb prop file, and old enough to be started prior to editing peg's files are technically clean. I bet, once I negatively cross the threshold, they'll be affected aswell.
What I did now was creating a new region, same plugin setup, fired up a large city, zoned it entirely in sprawltype manner just like my main region, let it develop till it crossed the critical threshold and checked the save file. No corruption.
Then I bulldozed to drop below the critical value, checked the new save... and to my surprise, I was not able to reproduce my previous observation of the pox striking me on negative crossing of the threshold. Not even on multiple attempts I wasn't (luckily the game can run on it's own most of the time so I could do other things, took quite some time to test this).
So, applying this finding to my above mentioned city, it wasn't the threshold crossing either that triggered the pox.
Now all that seems to be left to think about is what I did to the city in between the uncorrupted backup and the corrupted current state. If it wasn't for the deleting work, it must be for the plopping work.
But also here, testing of the relevant files (luckily it was just 2 sets of puzzlepieces) I used turned out to be no factor to the pox either.
So, long story short, I have a clue of being poxed due to peg's - despite the malicious outturn still considerably good - creations, but the outcome is rather random than predictable. For me at least.
Now I think of making a bunch of screenshots and restarting the 2 poxed and 1 infected city tiles from scratch... or abandon years of work completely as there's no definity cure to the disease, just a work-around to surpress the symptoms. That said, can I actually, thinking of my above mentioned testing phase and it's apparent results, consider an obliterated and then rebuild city tile as more or less safe from pox, or would it be in vain to try it?


Another point, aiming at really getting rid, some of the earlier pages suggest to extract several prop files from the games root data and making them zzzz thingy plugins so they load after probably affected lots.
Did anyone actually follow this idea already? From my logic, the game loads it's basic content, then the plugins, overruling the games content if necessary by simply being loaded afterwards. Now if someone would go ahead and, again, overrule the relevant props by a zzzz plugin with the maxis standard values, shouldn't this mean that at least for altered maxis content, the cause of prop pox would be eliminated? If I had the time, I would give this a shot myself as I did something similar for a modd related to grass textures which I presented over at the Simtropolis so I do at least hold the basic knowledge fiddling around with the reader to do so, but unfortunately I'm in the hot phase of ATPL exam preperations so if there's one thing I have even less than money, it's time

Another, totally head-in-the-clouds idea that crossed my mind, but I guess this wont be possible both for legal and coding issues, is to force the game to stop messing around with compression. From what I learned until now, there seems to be a strong correlation between the outbreak of the pox and the game's urge to fiddle around with compressed data. I don't get the point of compressing small files but not compressing large files anyway.

[bap]

GMT, thanks for your detailed post and testings.

from 95 more or less developed city tiles all under the same plugin setup ... 1 is infected and 2 others are poxed. everything else is pox free per bap's definition a few pages back. Development is suburban sprawl style with LOADS of low density buildings ... needless to say I am literally splattered with props so crossing the 16mb threshold is mandatory rather than optional in many cases.
curious tho, the region was started prior to my findings of what prop pox is, thus prior to what bap does suggest to alter in terms of peg's files, but definitely they were on board ... so basically this would mean that I am bound to be poxed sooner rather than later.

As I learned from the previous pages, sc4 save is considered a sureshot in terms of identifying the 3 states of pox free, infected and poxed, that's why I ran all cities through it, one by one.
What lead me even further into confusion, as one of the poxed cities is available in a backup file which is according to sc4save, not poxed and not infected (namely 0 disabled props, no poxed warning). the prop file is well beyond 16mb in this "clean" version.
So both the infection and the outbreak must have happened later on. Only changes to it tho are as recent as within the last fortnight, when I demolished quite some parts and the prop file dropped well below 16mb. I guess same accounts for the other poxed city, I did some minor changes but have lots of midrise buildings, many of which are grown C$$, so there was in fact a growth circle as explained earlier. As the prop file is just below 16mb, I guess once more the reason is in crossing the threshold backwards, keeping in mind that other cities positively crossed the threshold and stand unaffected according to sc4 save.

For the following discussion I will assume the cause of your Prop Pox are the 4 props defined in Peg's BDK-resource file. Given that, in order to get Prop Pox your city needs to meet all three following conditions:

1) low-density R$ or R$$ residential lots must grow in your city while the (unmodified) BDK-resource file is in your plugins folder. It does not matter if you remove the BDK-resource file after a while. All such lots grown while the BDK-resource file were in your plugins folder might lead to Prop Pox at some point in the future; (As you figured out by using the virus detector file, it seems you have loads of residential lots with possibly affected props)

2) at least some of your affected lots must be replaced (upgraded by the game simulator with a higher wealth lot, or directly demolished by the Mayor). When a lot with an affected prop gets replaced, the offending prop becomes disabled (at this point we call the city 'infected');

3) the props subfile must reach the 16Mby limit from below, i.e., it must fill the 16 Mby buffer set for compression for Prop Pox to finally appear.

By demolishing a sizeable fraction of your city you probably deleted several lots with affected props (all of which became disabled) and you also reduced the prop buffer below the 16 Mby limit. Any further development which brings this buffer again above the 16 Mby limit leads to Prop Pox as now it contains disabled props. So, it is not crossing the limit backwards which drives Prop Pox, but it is crossing it again forward when it contains disabled props.

It is possible to go beyond the 16 Mby limit without getting Prop Pox. All you need is no disabled props. And this can be achieved by preserving the offending lots from being replaced. This sets up an interesting way around of being infected: set all offending lots as historical. (you need to find them all, and you must do it before any of them gets replaced). Now, if your development is such that old lots do not get replaced (for example, no increase in population EQ to drive upgrading of R$ to R$$ residences), you have a chance of going beyond the 16 Mby limit without getting the pox, even if affected lots grew in your city. This is possibly what happened with most of your grown unpoxed cities.

Cross searching the web led my to simforum.de where diggis is cited with a probable solution similar to the one Z named here. I tried this and the prop files in both poxed cities doubled in uncompressed size, thus positively crossing the 16mb threshold again.  Still poxed according to sc4 save tho, but at least for one saving process, all props remained visible.

Diggis and Z procedures are attempts to restore an already poxed city, and are essentially the same procedure. Unfortunately it seems it just postpones the problem. If you keep playing the city, it will become poxed again.

What I did now was creating a new region, same plugin setup, fired up a large city, zoned it entirely in sprawltype manner just like my main region, let it develop till it crossed the critical threshold and checked the save file. No corruption. Then I bulldozed to drop below the critical value, checked the new save... and to my surprise, I was not able to reproduce my previous observation of the pox striking me on negative crossing of the threshold. Not even on multiple attempts I wasn't (luckily the game can run on it's own most of the time so I could do other things, took quite some time to test this).

May I suggest you (i) use the virus detector to figure out which lots might be affected, (ii) check whether these lots are being destroyed when you bulldoze parts of the city (and if they consistently generate one disabled prop per lot), (iii) let your city develop further, in order for the 16 Mby prop subfile limit to be crossed upwards again.

Now I think of making a bunch of screenshots and restarting the 2 poxed and 1 infected city tiles from scratch... or abandon years of work completely as there's no definity cure to the disease, just a work-around to surpress the symptoms. That said, can I actually, thinking of my above mentioned testing phase and it's apparent results, consider an obliterated and then rebuild city tile as more or less safe from pox, or would it be in vain to try it?

Again assuming that your Prop Pox is caused by the BDK-resource props, if you correct the aforementioned props, obliterate the Poxed cities and start again, you should be free from Prop Pox in these new cities. I restored all cities in my region which were either poxed or infected with backups from before I installed the BDK-resource file, modified the offending props, and continued developing these cities from that point without any further symptom of Prop Pox. The two larger ones have now gone beyond the 16 Mby limit without problems. Thus, yes, it is worth rebuilding.

A tip for the city rebuilding task: If you have two computers that you can run SC4 side by side, you can start the game with the old (poxed or infected) city in one computer, move the CD to the other computer, start the game in the other computer with the new (pox-free) version of your city, and use the old one to guide you rebuilding the new version. If you are up to preserving details, this allows you to reproduce exactly the same transportation, water, energy and city zone design as before.

Another point, aiming at really getting rid, some of the earlier pages suggest to extract several prop files from the games root data and making them zzzz thingy plugins so they load after probably affected lots.
Did anyone actually follow this idea already? From my logic, the game loads it's basic content, then the plugins, overruling the games content if necessary by simply being loaded afterwards. Now if someone would go ahead and, again, overrule the relevant props by a zzzz plugin with the maxis standard values, shouldn't this mean that at least for altered maxis content, the cause of prop pox would be eliminated?

It does not work  . This is equivalent of editing/correcting the offending props with the Reader. It corrects all new occurrences of that prop growing in your city from that time onwards, but it cannot change the offending props in already grown lots, as these are already stored in the savegame file. And we cannot modify the records already stored in the prop subfile unless one deciphers the checksum algorithm used to build the props buffer. If/when this is done, it will be possible to restore infected/poxed cities. (although Mrtnrln may have found a way around this.)

Another, totally head-in-the-clouds idea that crossed my mind, but I guess this wont be possible both for legal and coding issues, is to force the game to stop messing around with compression. From what I learned until now, there seems to be a strong correlation between the outbreak of the pox and the game's urge to fiddle around with compressed data. I don't get the point of compressing small files but not compressing large files anyway.

Yep, the fixed size of the props buffer required by the compression scheme is crucial in leading to Prop Pox. But modifying the game's compression scheme requires access to the .exe source -- which seems out of question. Several things Maxis did (or did not do) might sound meaningless from todays point of view, but just remember that this game is from 2003, when cpu power, ram memory and HD disk space were considerably lower than what is now available (just as an example, the whole original Maxis game files are no more than 600 Mby because it has to fit into cd-roms, while most users nowadays list the size of their plugins folders in terms of several Gbys, just of custom content).

[GMT]

By demolishing a sizeable fraction of your city you probably deleted several lots with affected props (all of which became disabled) and you also reduced the prop buffer below the 16 Mby limit. Any further development which brings this buffer again above the 16 Mby limit leads to Prop Pox as now it contains disabled props. So, it is not crossing the limit backwards which drives Prop Pox, but it is crossing it again forward when it contains disabled props.

It is possible to go beyond the 16 Mby limit without getting Prop Pox. All you need is no disabled props. And this can be achieved by preserving the offending lots from being replaced. This sets up an interesting way around of being infected: set all offending lots as historical. (you need to find them all, and you must do it before any of them gets replaced). Now, if your development is such that old lots do not get replaced (for example, no increase in population EQ to drive upgrading of R$ to R$$ residences), you have a chance of going beyond the 16 Mby limit without getting the pox, even if affected lots grew in your city. This is possibly what happened with most of your grown unpoxed cities.

although this explanation does what it's supposed to be - explain - I find some contradictions to what I witnessed. The "oiriginal" state (as in prior to reworking started) was 0 disabled props, at 25mb prop file. then I bulldozed considerable parts of low dens. R$$ thus dropping below 16mb and then I visually discovered the pox across town already, no need for a positive crossing in this particular case.

May I suggest you (i) use the virus detector to figure out which lots might be affected, (ii) check whether these lots are being destroyed when you bulldoze parts of the city (and if they consistently generate one disabled prop per lot), (iii) let your city develop further, in order for the 16 Mby prop subfile limit to be crossed upwards again.

hm...
as for top1: well, as it is mainly the same buildings, I don't think I need to run the virus detector again in this one, be assured affected lots are present. a wide majority of the development is huston tileset low dens. R$$ in both the original region and the testing grounds and by checking the original region, I found plenty of the respective props, so logic asures me that it's a waste of time to run the check again, albeit a small one, since the variation in maxis' lotting is a neglectible factor on fully developped large tiles.
as for top2: for similar reasons I am pretty sure that also affected lots are bulldozed. I did bulldoze about half the tile each time to definitely get below 16mb, like I said no disabled props whatsoever.
as for top3: that's what my testing was all about, crossing the 16mb threshold multiple times to prove my theory, or to falsify it.

Again assuming that your Prop Pox is caused by the BDK-resource props, if you correct the aforementioned props, obliterate the Poxed cities and start again, you should be free from Prop Pox in these new cities. I restored all cities in my region which were either poxed or infected with backups from before I installed the BDK-resource file, modified the offending props, and continued developing these cities from that point without any further symptom of Prop Pox. The two larger ones have now gone beyond the 16 Mby limit without problems. Thus, yes, it is worth rebuilding.

since I edited out any instance of the 4 affected props you initially determined that I came across digging through peg's resource files on my system and thereafter haven't come across an instance of pox, no matter if forced attempt or by chance, I assume these 4 props to be the only cause so far. My guess was that obliterating and rebuilding it would help, just wanted another thought on this one.

A tip for the city rebuilding task: If you have two computers that you can run SC4 side by side, you can start the game with the old (poxed or infected) city in one computer, move the CD to the other computer, start the game in the other computer with the new (pox-free) version of your city, and use the old one to guide you rebuilding the new version. If you are up to preserving details, this allows you to reproduce exactly the same transportation, water, energy and city zone design as before.

Why haven't I thought of this?? seriously, working on 2 systems parallel is something I do quite often, it should have come to my mind aswell. duh.

It does not work  . This is equivalent of editing/correcting the offending props with the Reader. It corrects all new occurrences of that prop growing in your city from that time onwards, but it cannot change the offending props in already grown lots, as these are already stored in the savegame file.

I didn't think of it as a cure, but more like a jab to at least give a chance to prevent future occasions. It would also come handy for those that have no experience with the reader.

Yep, the fixed size of the props buffer required by the compression scheme is crucial in leading to Prop Pox. But modifying the game's compression scheme requires access to the .exe source -- which seems out of question. Several things Maxis did (or did not do) might sound meaningless from todays point of view, but just remember that this game is from 2003, when cpu power, ram memory and HD disk space were considerably lower than what is now available (just as an example, the whole original Maxis game files are no more than 600 Mby because it has to fit into cd-roms, while most users nowadays list the size of their plugins folders in terms of several Gbys, just of custom content).

see that's exactly why I dont get the logic in compressing small (sub)file sizes and not compressing large ones, instead of the other way around or even compressing both. the only reasonable explanation I could make up is that the devs thought that such large subfiles have a very remote chance to occure.

[Lowkee33]

Hi all,

May I suggest you (i) use the virus detector to figure out which lots might be affected, (ii) check whether these lots are being destroyed when you bulldoze parts of the city (and if they consistently generate one disabled prop per lot), (iii) let your city develop further, in order for the 16 Mby prop subfile limit to be crossed upwards again.

A few questions.  Is there a way to guarantee a prop will become disabled?  Are disabled props the only cause of prop pox?

see that's exactly why I dont get the logic in compressing small (sub)file sizes and not compressing large ones, instead of the other way around or even compressing both. the only reasonable explanation I could make up is that the devs thought that such large subfiles have a very remote chance to occure.

This happens because there is a limit to the data the game can compress (0xFFFFFFFF bits I believe).

[RippleJet]

This happens because there is a limit to the data the game can compress (0xFFFFFFFF bits I believe).

Actually just 0xFFFFFF

The algorithm to decompress these files goes like this:
Read the 9 byte header, which is formatted like so:

Offset 00 - Compressed Size of file
Offset 04 - Compression ID (0x10FB) (QFS Compression.)
Offset 06 - Uncompressed Size of file

At offset 09 starts the compressed data itself.

For some really strange (and stupid) idea, the formatting reserves
32 bits (4 bytes, offsets 00, 01, 02 and 03) for the compressed size of the file,
but only 24 bits (3 bytes, offsets 06, 07 and 08) for the uncompressed size of he file.

Thus, as soon as the size of the uncompressed file exceeds 0xFFFFFF (16,777,215) bytes (or 16 MB),
it becomes too big for the compression format...

[catty]

This happens because there is a limit to the data the game can compress (0xFFFFFFFF bits I believe).

The "Mod the Sims" goes into more detail on DBPF Compression and how it works

see links

http://www.modthesims.info/wiki.php?title=DBPF_Compression

http://www.modthesims.info/wiki.php?title=Sims_3:DBPF/Compression

http://www.modthesims.info/wiki.php?title=DBPF