Welcome to the forum!
EB-FAQ, don't forget to read this!

You have installed the 1.2 patch into a wrong location, it has to be installed into the exact location as 1.2, meaning the main RTW folder, not the mods subfolder. After you selected the root RTW folder you'll have to delete the text in the [].

Don't forget the fixes: https://forums.totalwar.org/vb/showthread.php?t=80270

XSamatan