I recently had an issue when Adobe Acrobat Reader kept failing to update. The error message has disappeared but effectively said that a particular file could not be updated as it had already been updated by another application. The file and path were ‘C:\Program Files\Adobe\Acrobat Reader DC\Reader\AcroCEF\libcef.dll’.

I searched on-line for a solution and found several, none of which worked. The problem occurred again this afternoon so I decided to try an old trick. I simply renamed the DLL to ‘libcefold.dll’, restarted Adobe Acrobat Reader and ran the update again. It worked perfectly and installed the new version of the DLL without issue.

The update has installed and Adobe Acrobat Reader is working just fine. I hope this helps you because I spent quite a while trying the other fixes.

It’s possible that the update may fail for other files; you could try the same technique. If you rename a critical file, you may have to run the repair or reinstall procedure from Control Panel.

The above information is provided on an ‘as-is’ basis, I offers no guarantees and you perform the update entirely at your own risk.