Anything that prevents you from playing the game properly. Do you have issues playing for the game, downloading it or successfully running it on your computer? Let us know here.
If you have activated your key, and it comes up saying it is a duplicate then your account may have been compromised.
What do I do?
Don't panic
Please change your password
Email me at support@factorio.com, with the following info:
--The steam key you were given
--Your Factorio username
--The Email you used to purchase the game