Okay after a lot of research I found the solution and fixed it by myself.
For people having the same problem - here is my solution:
How to fix auto defeat?
Instructions: download the "launchers.zip" file from following site: https://www.gamerepl...wtopic=1010428 (direct link: https://drive.google...DrRaXr0jMHMM4Nn ) (If you have WinRAR, right click on the "launchers.zip" file and then choose "extract here".
If you have Windows 8, 8.1 or 10, no need for WinRAR, just right click on the "launchers.zip" file and then choose "Open with >> Windows Explorer".) open the "launchers" folder, and then do following:
if you get automatic defeated in Battle for Middle-earth 1 , put these files in the game directory of BFME 1. lotrbfme.exe, lotrbfme.dif, lotrbfme_manual.diff (Game Directory of BFME 1: This PC/ Local Disk (C:)/ Program Files (x86)/ EA GAMES/ The Battle for Middle-earth/ )
if you get automatic defeated in Battle for Middle-earth 2 , put these files in the game directory of BFME 2 lotrbfme2.exe, lotrbfme2.dif, lotrbfme2_manual.diff (Game Directory of BFME 2: This PC/ Local Disk (C:)/ Program Files (x86)/ Electronic Arts/ The Battle for Middle-earth II/ )
if you get automatic defeated in Rise of the Witch-King , put these files in the game directory of ROTWK lotrbfme2ep1.exe, lotrbfme2ep1.dif, lotrbfme2ep1_manual.diff (Game Directory of ROTWK: This PC/ Local Disk (C:)/ Program Files (x86)/ Electronic Arts/ The Lord of the Rings, The Rise of the Witch-king/ )