Given there is a cause and effect with the Community Folder, it may require you to start isolating which Mod(s) may be contributing to a failed Start Condition.
The rule of thumb is to cut your Community folder in half, load one half in and see if the condition persists. If it does, then your suspect mods are in that half. Rise and repeat. If the condition doesn’t occur, try the other half.
The other way is to ensure all Mods are updated, and the authors confirm they’re SU12 compatible and tested. Some websites that host Community Mod source files provide this rating, others may require independent confirmation. Remove the ones that aren’t certified and test again.