Fired up a game in Universe Mode.
I simmed through the end of Free Agency and the game appeared to be stuck 'Processing' between Free Agency and Training Camp.
I left it this way for about an hour. Esc didn't do anything, but hitting Ctrl-F4 caused a popup telling me the game wasn't saved and I would lose progress.
I cancelled that and the game returned, but the Advance button was **** and unclickable.
After reloading the league I was able to resume playing.