Can you please open support Ticket and supply us Download link to compressed MM5.DB?
There is one thing you should try:
1. Use file -> Manage database -> Backup database Now
2. Copy backup in safe place
3. Select only Rebuild Full Index and Rebuild Database and execute with OK.
That should resolve issue, but still it woudl be nice that you supply us DL link to compressed MM5.DB so that we can analyze where corruption happen.