yea, reason why I stopped playing the career I had it just corrupted outta nower. Try this. Backup your original save file (rename it to something else random). Go offline create another myleague save then turn off the game and replaced that file with your original just rename it to the same filename as the new save. Start up myleague and it should load fine. Then go back online.
How to go offline
If your playing through steam, open steam then click steam at the top then go offline.