As discussed here (https://community.simtropolis.com/forums/topic/74973-mmp-double-click/), it appears there is a bug with MMP sets that use multiple models on the same button. As far as I am able to tell, THIS IS AN UNFIXABLE WIN10 BUG IN THE EXE. The only possible full solution is to separate each MMP prop into its own individual menu icon, as with the vanilla Mayor Mode trees. If anyone else running the game on on Windows 10 can confirm they have this problem, please do.
EDIT: Found an old thread but it's too outdated to be of much use... (http://sc4devotion.com/forums/index.php?topic=17070.0)
EDIT2: As mentioned in the linked thread, holding the right mouse button when clicking seems to work. This changes the problem slightly, it appears SC4 has two "channels" for mouse button input, and for whatever reason this bug flips two at once, though that doesn't solve the problem that this appears to be a hardcoded bug potentially related to long-removed garbage code in older versions of Windows.
Yep I can confirm the issue on my end with windows 10 & gog version of the game. It appears like both mouse press and mouse release are registered as a click, meaning the game effectively plants 2 items in a single gesture. I interpret it this way because I can, for instance, plop 3 items from an MMP which has 5. Supremely annoying, to say the least. . %wrd
Will investigate possible solutions later on.
edit to reply to edit2; can also confirm holding down the right mouse button does indeed work but needless to say that's far from a solution as now the slightest mouse movement will slather mmps all over the place.
No solution, but a confirmation of the phenomenon (kinda, because I'm not 100 % sure).
I noticed mmp's clicking twice, but I wasn't really sure it was the game or my sloppy clicking (I hadn't played for a while)
Also Win10 and gog version btw.
Hmm... Seems like it might be a Win10 issue then. Windows Vista, 8, 8.1 and 10 removed a lot of problematic garbage code that a lot of programs on this list (http://www.testtrack4.com/cracked/appcompatlist.txt) rely on to function. SC4 is on that list, and this input bug could very well be the reason why...
Just info for you that may (or may not, I'm not a computer-savvy person) be helpful to you.
Win 10 also broke the legacy software for my favorite old gaming keyboard, a Steelseries Merc Stealth. Best I can figure out from searching the net, that was due to changes in the Windows installer. I have repeatedly rolled back every Win 10 update that broke it, including the Fall Creator's Update (twice, it tried to reinstall itself). I am currently playing the steam version of SC4, (hardware rendering and a wireless mouse) and do not have any issues with MMPs. I just used one last night that had 7 models, and each clicked fine for me.
If you think it would help, I can retrieve the numbers on the updates I've uninstalled, just let me know.