Hi, I would recommend opening a support ticket for this as there will need to check your policy store.
Are you seeing in the smps.log "Assert failed" entries?
That is a sign that some expected records are not found.
See if you can run XPSExport -xb export.xml and export successfully.
If you can, you will need to provide that when you open a support ticket.
If you fail to export, you will also need to share your XPSExport.log file.
If your policy store is LDAP, you should provide ldif export.
That way, support may be able to find which objects are missing and what actions can be taken.