Thanks for chiming in =) -- the last time I looked into the design tool stuff is quite a while ago, so my memory is kind of fuzzy, but I do remember I thought I was able to track down the colour variant switching to something in /tuning, which prompted
this post over at mts Create (I wasnt able to get that decompiled, and somebody uploaded it then and explained how they got it to work). This was prompted by having made catalogue objects like the "No-Drop" cabinets in
this upload post which only consist of a custom COBJ and OBJD, everything else is Maxis, and they were still throwing those Script Failed errors when attempting to design tool them. I also got exceptions left and right when I broke those catalogue objects in various ways (mostly to do with the group and instance I think, since that also plays a role in getting the module selection to work), most or all involving /tuning/instance_manager.py.
This was all in a much older game version though, I dont know whether that code is still the same and/or whether I'm even right about instance_manager.py having anything at all to do with the design tool. Just thought since you're a lot more Python literate, maybe you have poked at that issue before and would know more about it.
