I also got the problem. I was coming from an "addon" I have made myself for testing. (And was running correctly in 1.30). By removing the addon it worked ok. I suppose that I was lucky that the problem was coming from my addon, I suppose it may come from any other addons, and then is more difficult to find... It seems that BIS has added some checkings about addons (linked to some config.cpp modifications that are no more allowed). This is confusing because I do not know how to check what is allowed or not in config.cpp modifications !
So you can probably solve your problem by removing addons. Only one or 2 of them are causing the problem I suppose.