Solution. 1. You must to find "modified.log" in C:\Users*YOURUSER*\AppData\Roaming\The Creative Assembly\Shogun2\logs and open that file. It lists the files that are modified. 2. You need to delete them from C:\Program Files (x86)\Steam\steamapps\common\Shogun2\data.

Usually these files are

local_en_patch.pack unknown file patch.pack unknown file patch10.pack unknown file patch11.pack unknown file patch12.pack unknown file patch13.pack unknown file patch14.pack unknown file patch15.pack unknown file patch16.pack unknown file patch17.pack unknown file patch18.pack unknown file patch19.pack unknown file patch2.pack unknown file patch20.pack unknown file patch21.pack unknown file patch22.pack unknown file patch23.pack unknown file patch3.pack unknown file patch4.pack unknown file patch5.pack unknown file patch6.pack unknown file patch7.pack unknown file patch8.pack unknown file patch9.pack unknown file patch_bp.pack unknown file patch_fots.pack unknown file patch_fots2.pack unknown file patch_fots3.pack unknown file patch_fots4.pack unknown file patch_fots5.pack unknown file patch_movies.pack unknown file patch_movies2.pack unknown file patch_movies3.pack unknown file patch_movies4.pack unknown file patch_movies5.pack unknown file patch_movies_fots.pack unknown file patch_movies_fots2.pack unknown file shaders_patch.pack unknown file shaders_patch10.pack unknown file shaders_patch11.pack unknown file shaders_patch12.pack unknown file shaders_patch13.pack unknown file shaders_patch14.pack unknown file shaders_patch2.pack unknown file shaders_patch3.pack unknown file shaders_patch4.pack unknown file shaders_patch5.pack unknown file shaders_patch6.pack unknown file shaders_patch7.pack unknown file shaders_patch8.pack unknown file shaders_patch9.pack unknown file

And/Or validate your game cache.