Another idea: I installed the mod as everyone, so the only problem could be in the following My Games\BtS dirs: assets, CustomAssets. The other dirs are either empty (Patch etc.), ineffective (e.g. Screenshots) or made by the mod (BUG Mod & MODS). Would it make any sense to compare my assets/CustomAssets lib contents to yours?

Well, since the MOD and the install were correct, and you haven't met this phenomenon before, the problem can be only with my BtS install. I'll try to reinstall later this week, if I'll have time to do that. Thank you for your help and time, I really appreciate it
Keep up the good work! 