And just to add to this...
If you find a suspicious looking entry in the auditbase table, you can try opening up the Audit History of that record but if any of the records in there are problematic, you'll get the error message. However, if you look at the date and time of the entry
in the auditbase table, you can always go into the Audit Summary View via Settings -> Auditing and find the particular entry. Try opening it and, if it errors, then it could be the cause. You can then keep doing this until the Audit History works again.