How to Fix Firefox – Unable to Download or Save Files

I recently came across a problem with my Firefox browser in which I suddenly could no longer download or save files. Ironically, this was just after I installed AVG 2012. Obviously, I knew that there was some sort of problem between the two flagship programs on my Windows 7 desktop computer.

After scouring the forums, the help articles and using Google to its fullest, I came up empty-handed. Everything I tried had the same result – something was deleting my files after I downloaded them in Firefox. In fact, I could watch the files being downloaded, see the temporary file in my downloads folder and when the download was complete – “poof” it was gone.

Here’s some of the things I tried that didn’t work:

Reinstalled Firefox three or four times (even tried the beta).
Changed the download folder location.
Completely removed Firefox and installed a new copy of Firefox 6 (that I had to download via Chrome).
Uninstalled AVG.
Installed a different antivirus program.
Created a new Firefox profile.
Deleted the downloads.sqlite file so Firefox would create a new one.
Created a new Windows user profile.
Cleaned and tweaked with CCleaner.
Ran Malwarebytes.
Ran Spybot Search & Destroy.

After everything with done, I still couldn’t keep my downloaded files from deleting themselves. That was until I came across this little tidbit on the Mozilla support site:

Firefox launches your installed antivirus program to scan files when they finish downloading. In some cases this can cause a substantial delay or downloaded files may not be saved after the scan completes.

Hmmm, could that be the problem? Sure enough, after I changed the browser.download.manager.scanWhenDone setting to false in the about:config window I could download files without any problems. How I missed that part of the article in my initial search was baffling to me, but I’m glad that I can again download files with Firefox. It just goes to show you that even the best of us can miss the simplest of fixes.