This has happened twice now and I couldn't find a solution on the forum.

While playing career mode, sometimes I can't sim the current week. I have played multiple seasons with this league and it just happened again. I also can't use the sim season button either. The only way to progress with the game is to use the sim multiple seasons button and tell it to sim just one season. Then it seems to work like normal again.

If anyone has a solution to this I would appreciate it if you could share it with me. Thanks.

It is probably due to an invalid roster or depth chart for your team. Simming multiple works because it sets your team to cpu and the cpu fixes things.