Hi Mordim,
It sounds like you have single player mods installed that are conflicting with Bannerlord Online. Check the steps below to see if it will resolve your issue.
- Disable all single player mods in the base game Launcher. Try launching Bannerlord Online.
- (Temporarily) Remove the mods from Bannerlord.
- Create a new folder in a location convenient for you.
- Navigate to the Bannerlord Modules folder. "\SteamLibrary\steamapps\common\Mount & Blade II Bannerlord\Modules"
- Move all single player mods to the new folder created in step 1 and try launching Bannerlord Online. Only the following mods should remain.
- BannerlordOnline
- CustomBattle
- Native
- SandBox
- SandBox Core
- StoryMode
- BirthAndDeath
- Verify the game files. See steps for "The Game had an update" above.