We will investigate the problem.

Could you please provide us with your save game by posting it here as a ZIP file attachment and let me know the steps for triggering the bug with the save game?

If your savegame uses a MOD, please provide us with the MOD files as well. You may either provide us a direct download link to the MOD or you may ZIP the MOD files in your MOD folder together with the save game file.

I get this error message during game-play. After pressing OK it quits. Btw, I'm playing with a MOD.