The last game update from Creative Assembly has broken some mods for Napoleon Total War. In this page you can download old game files, follow the instructions to revert to the previous state of the files before the update and your mod should work. It works for The Great War mod, I will test with other mods and inform here, if it worked for you with another mnod please share the info in the comments to help other players! thank you.
Step by Step how to enable ModManager to work again after CA patch May 2023
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