Your mod is awesome. I'm using it all the time. Today i had added campus dlc and few extra mods, and after that saw a message below.

The Mod /Users/bogdandychko/Library/Application Support/Steam/steamapps/workshop/content/255710/1890830956 [UndoMod.dll] has caused an error [ModException]

Details:
System.NullReferenceException: Object reference not set to an instance of an object
at UndoMod.Patches.BuildingManagerPatch.Unpatch (Harmony.HarmonyInstance _harmony) [0x00000] in <filename unknown>:0
at UndoMod.LoadingExtension.OnLevelUnloading () [0x00000] in <filename unknown>:0
at LoadingWrapper.OnLevelUnloading () [0x00000] in <filename unknown>:0