I attempted to link my shift account to begin playing multiplayer, however my launcher crashed in the middle of the process. Upon closing it and restarting it, I found I could no longer start any of the games. I would select one, then the an outline of a window would appear in the middle of the screen, with the upper right only appearing. It also locks my mouse and the only way to close it is to alt-tab to do so. I tried deleting it and reinstalling it, however the issue still persists. Any suggestions would be greatly appreciated.
For me it sounds that the player profile is corrupted, I would try to delete them from the game folder:
Make a backup first