make sure that ur game is updated to version 1.7 for it to work and it takes 3 to 4 tries to get it working  when clicking on the solo button

Turns out all it took was a WaW reinstall

I have T4M downloaded and I put my texture settings as low as they go (low) and it still comes up with the same error.

I've reinstalled the fortress map pack 3/4 times and i keep getting the error: Server script compile error unknown function maps\_challenges_coop::unlockAttachment(attachmentunlocker );

Is there any fix for this?