3 months ago - PDX Katten - Direct link
I suggest checking if the mod is up to date with your version of the game.

Very old mods normally do not work with the latest version of the game.
2 months ago - PDX Katten - Direct link
Last version is 1.14.6 [Checksum: 5a08], released June 10th.

Have you tried for example Road to 56 or Kaiserreich? They are updated to that version, if those dont work then I recommend verifying your files as something is wrong.