The chain may have forked, resyncing the block files might fix this. I'll send a message to the developer to see what is going on.
how to resyncing the block files?
Well there is probably nothing wrong at your side, so local sync wont help. Will have to wait for CryptoDatabase to get his answer from developer. But wait something just happened, i just received my stake. How does it look at your side? My wallet shows its fully synced with the network up to block 796. Strange. And now block 797 and rising, i believe we are ok.
i restart my wallet after i saw your post..and yes it is ok now..block 798..thanks!