Hello,

First of all, you should update to version 23.0.

Try Firefox Safe Mode to see if the problem goes away. Safe Mode is a troubleshooting mode, which disables most add-ons.

(If you're not using it, switch to the Default theme.)

• You can open Firefox 4.0+ in Safe Mode by holding the Shift key when you open the Firefox desktop or Start menu shortcut.
• Or open the Help menu and click on the Restart with Add-ons Disabled... menu item while Firefox is running.

Once you get the pop-up, just select "'Start in Safe Mode"

If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, and you need to figure out which one. Please follow the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article for that.

To exit the Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.

When you figure out what's causing your issues, please let us know. It might help other users who have the same problem.

Thank you.

If downloads hang at the last minute (just before reaching 100%), the cause might be antivirus software which tries to scan the file and during that process hangs the Firefox instance.

In order to fix the problem, try disabling the scanning as follows:

1. In the Location bar, type about:config and press Enter. The about:config "This might void your warranty!" warning page may appear.
2. Click I'll be careful, I promise!, to continue to the about:config page. A list of settings should appear
3. Filter the list by typing in the search bar at the top. Type in scanWhenDone. You should now find the "browser.download.scanWhenDone" preference.
4. Double-click on that preference to set the value to false.
5. Next, try to download something and see if it still hangs.

Please reply and tell us whether this helped you!