This is the one to be alarmed by:
Database tools Rebuild Indexes and Compact may fix some of the possible causes. Drag’n’drop to a new database might succeed. GEDCOM export and import to a new database might but both DnD and GEDCOM may lose some stuff. That’s about as far as RM Support can go. Beyond that, somebody with SQLite expertise may be able to recover all or some of your data (e.g., link in that discussion).
Preventative measures include avoidance of other processes accessing the database while it’s open in RM, periodically checking your drive for degradation.
For recovery, routine backups from within RM plus other periodic backups to external drive, cloud, off-site.