FileMaker Damaged Files, Corruption, & Recover

Link TechInfo Article 102516

Damaged Files and Hidden Corruption in FileMaker Pro ( A Guide to "Recover" )

Posted 10/13/2003 ... Last Updated 12/1/2021   18th Anniversary

By Gregory Durniak

The following information is based on my experience as a FileMaker developer, FileMaker's TechInfo Knowledge Base, and on numerous discussions with FileMaker Tech Support, and FileMaker's Engineers.

I strongly recommend the product. It just needs better utilities !



Let me start out by saying that since FileMaker 10, Recover's closing "WARNING" is a bit misleading, and very unsettling. It reminds you to check the log for "problems", and their "severity", and that the Recovered file should NOT be used going forward. But, It should go on to say that "problem" objects CAN often be edited, or deleted, in the Original file going forward ( or ignored, if of "low severity" ), and that Recover CAN actually repair certain problems, going forward

The "Hidden" Corruption Problem

FileMaker Pro, and FileMaker Server will open and run files that are corrupt. I have seen this happen multiple times:

I understand that files can be corrupted by power surges, and by bad hard drives, and can NOT be prevented. What I don't understand is why FileMaker can not detect it. There is no validation utility ( FileMaker's Customer Support Services explained that since validation can never be 100% accurate, no utility is provided ).

When damaged files run, backups and "master" clones are useless. It is difficult to develop an effective backup strategy, when there is no way to be sure that the files you are backing up are OK ( see FileMaker 9 and FileMaker 10 improvements below ).

This problem was actually documented in FileMaker Answer ID 2943 "Strategies for Protecting Files Whose Structures are as Important as Their Data" "... Any time you make changes to your file's structure ... you will need to save a new master clone. Place your new master clone in a safe place... At this point, you have a clone with no records, but you may also have a file structure that is possibly damaged due to corruption carried over from the original file ..."

This problem was also noted in "FileMaker Server Best Practices" ( Rev 03-2003 p.13 ) "Any system failure causing FileMaker Server to shutdown inappropriately could result in corrupted files ... Even if the files seem to re-open but have to go through a consistency check or recovery, some corruption could be buried in the file"

What are your chances of getting "hidden" corruption? The four failures above are the result of five different organizations, each running an average of 24 files, for 5 years, using FileMaker's best practices.

Editorial Notes

Common Causes of Corruption

Removing Hidden Corruption

Removing Obvious Corruption

Corrupt Data

Corrupt Records

Damaged Layouts



The Recover Utility


How does SQL handle Corruption ?

Index Problems, "Phantom" Blank Records, and Question Marks in all fields

Grouped Objects Problems

Manage Scripts ( Scriptmaker ) or Manage Layouts Problems

Tech Specs

Make sure you haven't exceeded FileMaker's Technical Specifications, e.g. by defining 5,900 fields in FileMaker 5. The file may work, but appear to be corrupted

File Maintenance Options ( Prior to FileMaker 10 )


Before you run Recover

General Notes


Notes by FileMaker Version

FileMaker 7

FileMaker 8 / 8.5

FileMaker 9

FileMaker 10

FileMaker 11 and 12

FileMaker 13

FileMaker 18


What I would like to see

  1. Check File ( Read Only )
  2. Re-Index
  3. Re-Catalog ( Rebuild the Script list, Layout List, etc )
  4. Remove stranded library objects
  5. Rebuild ( Remove Damaged )

Tips on Re-Building a Damaged File

Copyright © Gregory Durniak | |