try this:
so your BattleTest Folder is in you Modules and the BattleTest.bat and BattleTest.dll are in the Win64_Shipping_Client folder right ?, did you try starting it with the BattleTest.bat ? and did you try to start it in Admin Mode?
if you open the launcher from Bannerlord and go under DLC is Battle Test selected ?
Thank you For your Hard Work
yes thats probably the case here
Still Crashes, maybe Taleworlds has Changed something, like Item IDs
after removing /singleplayer from the bat i could start the game but like potetflak, my game crashed after i clicked start battle
looks like it