Make a copy of the damaged file (right-click-and-drag its icon is an easy way to do this), and try to repair the copy. This is safer than doing surgery on your original file.
1. Firstly try running PAF's Repair function a few times on the file. File menu > Check/Repair Is PAF able to repair it?
2. If you have PAF Insight (or a friend or your local Family History Center has it) try opening it in PAF Insight. Was PAF Insight able to repair it?
3. Can you export the entire database as a gedcom file? Create a new empty PAF file using a new name (e.g. include the date in the file name) and import this gedcom. Did this solve the problem?
4. Do you have additional backups? Even if they are out of date, they may be your best option. But before restoring them, make sure they have different names from your current database. (Who is missing? The highest RINs usually indicate the most recently-added people.)
Once you have your database repaired, give it a suitable name and make a few backups. e.g. flash drives, CDs, email attachments ...
BACKUPS This comment is a reminder for all of us. We can't have too many backups, but we can easily have too few.
A key point is that the computer can only store ONE copy of a file with any particular name in any particular location. For example: If I have a file called Jones.paf, if I save/store any other file named Jones.paf (orrestore a backup named Jones.zip) in that location, the new file will erase and replace the older file with that name. With this in mind, we should:
1. Give each backup a unique name (e.g. include the date in the file name). That way when it is restored, it won't replace the current database.
2. If we give every backup the same name, the most recent one replaces the previous one stored in that location, so we only have one backup and if it becomes corrupted we can have huge problems.
3. We never backup a corrupted database with the same name as our latest good backup, because that will just replace the good backup with a bad one.
There are millions of possible file names. It is a false economy to use the same name for all backups. The average backup of a large database is less than 10 MB, and many are less than 1 MB. When a CD-R can hold 70 backups or more, there is no need to save space.
I hope this is helpful. I have PAF Insight at home and would be glad to try to repair a copy of your PAF database (no guarantee of success, but a good probability if you email me a backup). I would need specifics of what to watch firstname.lastname@example.org