I've been talking to EA Support today, and they gave me the following fix for my problem (Game froze at spawn screen with top-right message saying: 'Friend Left - Joining Cancelled' with the screen turning white when I alt-tab and Battlelog saying: 'Transitioning').
Step 1:
From the Start menu, select Computer.
Select the C: drive.
Select the ProgramData folder.
If this folder does not appear, press Alt, select Tools, then Folder Options.
Select the View tab, then check Show hidden files, folders, and drives.
Right-click the Origin folder and select Delete.
Step 2:
Now please try to repair the game from origin.
Step 3:
Launch the game and test if it works.
I hope this will atleast help out some of you.
[Edit]
I don't think this was the fix, but maybe it is. I restarded my PC and my game crashed again, but I noticed that when the game did run normaly I had turned off the AMD Raptr app, so when I restarded my PC Raptr was running again. So I closed Raptr again and my game runs normal again. So for all the AMD users that have this problem, try turning off AMD Raptr.