What causes Prop Pox (and how to avoid it)

[Jmouse]

Here's one I found helpful: {Link}. I've no idea if it has anything to do with prop pox. The 192 driver is notorious for causing graphic-display problems, though.

Later...
Joan.

[Duvad]

hmm, this is interesting

I have been developing one region for about 4-5 years now and never had prop pox. Then yesterday my most developed, and large-sized, city came down with it. After finding out about what it was and how it was incurable I restored a 3 year old back up of it just today. Then within a few hrs of developing the city so it came closer to its current state (played for about 8 years, but there was massive demand as you'd expect), prop pox was back. I don't get how in a few hours of development I could reach something that took me 3 years earlier to do.

Does that mean there's something new I may have installed causing it, or what? I have had that PEG BDK thing installed for aaaages and never had any issues until now, and I don't think I even used his stuff so far.

[RippleJet]

I have had that PEG BDK thing installed for aaaages and never had any issues until now, and I don't think I even used his stuff so far.

Whether you've used anything from that pack or not, is irrelevent.

The relevant thing is that certain Maxis props are included, and edited so that their timing is changed.
Since their TGI addresses are unchanged, they replace all such props in your game.

Those ingame props appear on dozens of ingame lots.
Thus, it's almost certain that you've got lots of those props in your city.

[SC4BOY]

I don't get how in a few hours of development I could reach something that took me 3 years earlier to do.

This has been reviewed in this thread several times, but again.. the lots that generate prop pox are like seeds or time bombs (should be renamed "compression bombs" in this case.. hehe). ONLY when you exceed the "compress" size.. approx 16Mb for the file to be "compressed" (the point where the lot size issue ends in "memory overrun" of a sort) does the "bomb" explode into "prop pox".. As long as that point is not reached you can happily play the city and never notice any symptoms.. then once you get to that size and save/reopen the city there it is in all it's glory (starting in one corner, NE as I recall, and working its way south and through the whole city as you continue).

Would be cool if we could figure out how to get the game not to compress the file. In today's computers the file size is pretty much irrelevant since HD storage is so cheap $/Gb. If it never compressed it would never show "prop pox"

[ElPhantasmo69]

I'm so confused! I've gone through the thread but I feel I've missed something. Is there a way to rescue a city that's been struck by Prop Pox? I've gotten rid of the offending plugins, but there's more I need to do, yes? Sorry for being so thick...

[SC4BOY]

Is there a way to rescue a city that's been struck by Prop Pox?

No

[Duvad]

Cheers for those answers. Although my city seems doomed if I do much development on its 3-year old back up I still want to be able to develop it so it properly supports the CO/CS needs of the region.

This might be a stupid question, but if I get rid of prop-intensive lots/plops (e.g. I have tonnes and tonnes of ploppable trees/forests/water), will it reduce the size of the uncompressed file (and thus extending the time I can develop the city before going over the limit)?

[SC4BOY]

...if I get rid of prop-intensive lots/plops (e.g. I have tonnes and tonnes of ploppable trees/forests/water), will it reduce the size of the uncompressed file (and thus extending the time I can develop the city before going over the limit)?

I won't swear to it, but my recall is that when you remove things, there still are "placeholders" in the save file. You could of course just test for yourself by downloading the tool SC4Save and look at the prop subfile of the save (and since you have a backup) do whatever you think you want to do to props lots, save it then look at it again with SC4Save and see for yourself if you have made a significant difference in the file size. As long as you can keep it below the compress size, you'll not see the pox

[z]

You can completely get rid of the pox any time you want... temporarily.  Here's how:

1. Open your saved city in Ilive's Reader.
2. Sort the left pane based on file size, with the highest at the top.
3. Near the top, there will be a subfile of type 2977AA47.  This is the prop subfile.  Delete it.
4. Also delete the subfiles of type 6A0F82B2 and 6990C1AA, which are also near the top.  These subfiles are regenerated as needed.  If you don't delete them, this process will still work, but your city size will increase greatly each time you repeat this process.
5. Save the city file.
6. Start up the game, but don't open the city file.
7. Open the Graphic Options, and make sure the City Detail is set to Low.
8. Open your city and save it immediately.
9. Exit to the region without saving.
10. Open the Graphic Options, and change your city detail to High.
11. Open your city.  All your props should be restored.
12. Save your city.  Your props will all be there... for a while.

[RippleJet]

This might be a stupid question, but if I get rid of prop-intensive lots/plops (e.g. I have tonnes and tonnes of ploppable trees/forests/water), will it reduce the size of the uncompressed file (and thus extending the time I can develop the city before going over the limit)?

The most common size of a prop record is 88 bytes, and the next common one (for timed props) is 108 bytes.
To get the prop subfile up to the size of 16 MB, would require some 190,000 props in a single city.

It might be difficult to find tens of thousands of props to delete, just by bulldozing some ploppable lots though...
And mayor mode ploppable trees aren't even saved in the prop subfile, they're in the flora subfile (0xA9C05C85).

On a large city, 256×256 tiles = 65,536 tiles, 190,000 props would mean almost 3 props per tile. Doesn't sound too much...
However, it's worth noting that low-density growable lots usually have a lot more props per tile than large skyscrapers.

[fafalone]

[...]

6)   It seems a memory overflow somewhere is leading to the corruption of the network subfile and the city save file ( see here ). There was a suspicion that the EP1 update program could be the cause of Prop Pox. Another possible culprit would be a plugins folder infected by multiple definitions of a same prop.

EP1 doesn't seem to cause it; it happened to the first city I built when I started playing again last year, at which point I didn't have any update installed, just the base version of Deluxe. I also had less than 500mb of plugins at that point. If multiple definitions of the same prop were the culprit, my memory isn't exactly clear but I don't think I removed anything from my plugins folder after that, and have built many more much larger cities (the city this happened to was only 20-30% development on a large tile) and the problem has not re-emerged, and I'll admit I'm sloppy with things like Cleanitols so there's gotta be dupes somewhere. The low level of development on the city this happened to, and some of my current unaffected cities that are large tiles covered top to bottom in plopped custom content from a 4.5GB plugins folder, makes me wonder about the size of the subfile theory. Might there be something different about this in regards to growable lots? The problem never happening after that coincided with a good deal of my cities being custom plopped.

Now I make regular backups.

Edit: Further, my largest city, built as described above, uses every single OWW2 lot including the file given as a cause, and somewhere between the backups it jumped from 13,844KB to 29,762KB. Interestingly enough, that was between Feb 28 and Mar 07 of this year. *If* I made any changes to that particular city (region backup) in that time period, it was small. Still no prop pox. The network subfile is 5,076,314; but I can't imagine a city with only a third of the land developed with a comparatively small amount of custom content could have had a network subfile above 6. There's got to be some interaction...

[RippleJet]

Edit: Further, my largest city, built as described above, uses every single OWW2 lot including the file given as a cause, and somewhere between the backups it jumped from 13,844KB to 29,762KB. Interestingly enough, that was between Feb 28 and Mar 07 of this year. *If* I made any changes to that particular city (region backup) in that time period, it was small. Still no prop pox.

Thanks, fafalone!
That's certainly a confirmation of the fact that the prop pox does not strike every time the prop subfile goes beyond 16 MB and from compressed to uncompressed.

This in turn gives confirmation to what we've suspected...
that one of the lots containing the mentioned props needs to be bulldozed or upgraded during that process.

The fact that few changes were made to the city between the saves would also indicate,
that you managed to get the 16 MB size to be surpassed at the right moment.

It would be interesting to see the prop subfile's size and number of records within it before and after it surpassed those 16 MB.

[fafalone]

Backup from Feb28 (13,844KB)
Prop subfile size: 5105613

Prop pox free city
149311 props found in city
Some infos about the props:
-0 disabled props found in city
-3898 tracking props found in city
-4570 timed over year props found in city
-22763 dayly timed props found in city
-27427 conditional props found in city
-From what kind of data :
--25 props alone
--129248 props from lot
--20038 props from T21

Backup from 3/7 (29762KB)
Prop subfile size:  5076314

Prop pox free city
148919 props found in city
Some infos about the props:
-0 disabled props found in city
-3904 tracking props found in city
-4566 timed over year props found in city
-22708 dayly timed props found in city
-27368 conditional props found in city
-From what kind of data :
--39 props alone
--128876 props from lot
--20004 props from T21



I really don't know where the difference in size comes from; all of the subfiles listed in savegame explorer are similar in size. If you want the files to analyze them, let me know. Or tell me what else to look for.

[RippleJet]

The prop subfile is far from being 16 MB in size...
Thus, you wouldn't even have to fear the the prop pox in the first place for quite some time.

[fafalone]

I went back through some old files and identified the city I was talking about that was only covering 1/3rd of a large tile with a fraction of the custom content.

Filesize: 3.2MB
Prop subfile size:895,727

Prop pox free city
26010 props found in city
Some infos about the props:
-1 disabled props found in city
-763 tracking props found in city
-10 timed over year props found in city
-5778 dayly timed props found in city
-5808 conditional props found in city
-From what kind of data :
--13 props alone
--23252 props from lot
--2745 props from T21

Now it says it's prop pox free, but what happened in the city is absolutely identical to what's called the prop pox. I'll post a screen shot to confirm later.

[RickD]

Thanks, fafalone!
That's certainly a confirmation of the fact that the prop pox does not strike every time the prop subfile goes beyond 16 MB and from compressed to uncompressed.

This in turn gives confirmation to what we've suspected...
that one of the lots containing the mentioned props needs to be bulldozed or upgraded during that process.

Sorry, I don't quite understand this. My poxed city develops the pox in pause mode. I have the city on pause with compressed file, force the file to uncompress -> pox. Nothing is bulldozed or upgraded.

[RippleJet]

I have the city on pause with compressed file, force the file to uncompress -> pox. Nothing is bulldozed or upgraded.

How do you get the prop subfile to increase beyond 16 MB while the game is paused?

[RickD]

I delete the subfile (which is close to the limit but still compressed) in the reader, load the city with low graphics settings, save and exit, switch to high, save and exit, reload, save and exit Then I end up with an uncompressed, poxed subfile.

[z]

That sounds correct.  But did you get your props back?

[RickD]

I get many of the props back for the one session after switching the graphics setting to high. After reloading the city they are gone again. Each time I reload the city, more props vanish.