Common Issues:

Problem: Instant “Mission failed” when starting a map.
Solution: Just close and restart the game. This could be caused by a recent game update, but only on the first run.

Problem: Mouse and Controller are not responding or messy.
Solution: Check out Controller Configuration. If the problem persists, find and delete the registry \HKEY_CURRENT_USER\Software\Deonn Software ltd.\Armed to the Gears

If you’re still having problems, check out the Community Forum, your answer might  be there.