Cannot get past the main menu.

Last night my main menu became unresponsive meaning that I cannot select any of the menu options with my mouse. Even plugging in a control doesn't allow me to navigate the main menu. This happened literally after exiting a server and not as a result of any downloaded patch or something.

I have repaired the installation with Steam and it's still not functioning.

Turned the PC off last night, woke up and it's the same thing again.

The only thing I can do in the main menu is press "Enter" which brings up "exit game yes or no" -> to which I cannot even select an option. As a result I'm forced to end the game from task manager to even get out of the main menu.

Un-installing and re-installing hasn't fixed this issue.

It's not some sort of issue with fullscreen as cycling through the video fullscreen settings with F11 produces nothing.

PC specs:

Windows 8.1
i5 4690k
AMD RX480
Installed on SSD

Please help me because I literally cannot play the game right now.

Cannot get past the main menu.