I tried reinstalling the game and syncing, but alas, it didn't help. All my efforts were in vain, except now you know that it's a pointless waste of time.
The final campaign can't be completed, and it kicks me out to Windows with an error message.
The issue with saves is also debatable.
On the one hand, you don't need many saves, but on the other hand, I have saves before each boss, and if I suddenly need to earn another achievement, I can easily spend 10-30 minutes, rather than replaying the entire campaign.
I remember that in parts 2-3-4-5, you could save in a multiplayer game and return after some time to finish it. Now, with the limit, this might be a problem.