Campaign Will Not Unlock

[OoJellyBeanoO]

Hi, I've been trying for hours to get this game working properly. I first had trouble with what I believe to be a resolution issue. To get around this issue, I booted the game up in safe mode, switched the resolution around and ticked the box to use windowed mode. Now that I have that out of the way, it appears that I can't start the campaign because all of the campaign levels are locked, including the first. When I launch the game, it automatically loads into a brand new sandbox mode. I then navigate to the main menu and it shows me that all of the campaign missions are locked.

I've verified the game files on Steam and found no issues, I uninstalled and reinstalled the game but still have the same issue. I'd also like to point out that I'm no longer launching the game in safe mode either (unless for some reason it's still launching in safe mode in the background even when I try to launch from the normal game file). Any help or guidance would be much appreciated, thank you.