I was playing the game with no problems for like 30 mins, then I quit to desktop. When I wanted to start the game again, there was a "Fix" button instead of "Play", so I clicked that. I then turned the game on again and now my hotbar looks broken. I can use items through shortcuts with no problems, but the hotbar looks... well... wrong.

FIXED IT: Alright, I figured out the problem. I'm not using an english keyboard, so the basic 1,2,3 shortcuts didn't work, as my keyboard has special characters instead of numbers, I binded those special characters instead of numbers and it worked. After reloading, the game had problems loading in the special characters, though. I changed the shortcuts to normal letters and now it's fine.