If you are having problems with Firefox Freezing, it could be an issue related to an extension or theme (Add on) that is incompatible with the Firefox version you’re using, or conflicts with another add on. The current version is 3.5.5.
As a quick fix, switch to the default theme or, if the problem appeared after installing a new extension or after upgrading Firefox, use the Add-ons manager (accessible from the Tools menu) to update or disable your extensions, before going through the diagnostic steps below.
It’s impossible to know which extension is causing the problem. You will have to go through the process of elimination to identify which extension (Add-on) is causing Firefox to freeze. It may be enough to just update all the extensions in “Tools -> Add-ons -> Extensions -> Find Updates”. Otherwise, the quickest solution to many Firefox problems is to check whether disabling all extensions helps.
- Start Firefox in Safe Mode (not Windows Safe Mode). When the “Firefox Safe Mode” window appears, press the button, “Continue in Safe Mode”. This will start the program with all extensions disabled and with the default theme.
- If the problem disappears when all extensions are disabled, restart Firefox normally and disable one extension at a time. Open the Extensions Manager via “Tools -> Add-ons -> Extensions”, then select at least half of the extensions and click the “Disable” button. Restart Firefox.
- If Firefox is acting normal and not freezing, than one of the extensions you disabled is the culprit. Make a note of what extensions you disabled, and enable about half of them.
- Restart Firefox and keep narrowing down the list of extensions by enabling half of the disabled extensions.
If the problem comes back at any point in the trouble-shooting process, you know that there is at least one incompatible extension in the group you just enabled, but keep in mind that there could also be other incompatible ones among the group you disabled. The only way of making sure that you find all incompatible extensions is to only ignore those groups that did not cause any problems when enabled.
For more troubleshooting techniques, visit mozillaZine.