Hi Sadzolini,
There's a thread for this issue in the Jewel Mania | Bugs and Issues section of the forum. I've had that problem a couple times. But luckily, they were easy levels. I just replayed them and was able to move on without further problems.
However, prior to replaying, I did all the recommended "things to try first"/usual fixes (I quoted them in another thread here.) And the post underneath that one has additional info.
Nowadays, I force close JM daily, and my iPhone at least once a week--kind of a "preventative measure" so it doesn't happen again! Good luck!