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Firefox freezes or locks up

  • 1 பதிலளி
  • 1 இந்த பிரச்சனை உள்ளது
  • 4 views
  • Last reply by cor-el

I recently did a fresh install of Windows. I'm back to Firefox and using Version 81.0.1 (64-bit). I've noticed that my browser will sometimes lag or freeze, and it does it mostly when switching between two tabs - sometimes with just one tab open it will lock up for about 5-10 seconds then go back to working fine. Is there anything I can check to see if something is causing this issue? It's becoming very annoying. I only have three extensions installed, and it was doing it before I added them back.

I recently did a fresh install of Windows. I'm back to Firefox and using Version 81.0.1 (64-bit). I've noticed that my browser will sometimes lag or freeze, and it does it mostly when switching between two tabs - sometimes with just one tab open it will lock up for about 5-10 seconds then go back to working fine. Is there anything I can check to see if something is causing this issue? It's becoming very annoying. I only have three extensions installed, and it was doing it before I added them back.

All Replies (1)

If you use extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) that can block content (Adblock Plus, NoScript, Disconnect, Ghostery, Privacy Badger, uBlock Origin) always make sure such extensions do not block content.

Firefox shows a purple shield instead of a gray shield at the left end of the location/address bar in case Enhanced Tracking Protection is blocking content. You can click shield icon for more detail and possibly disable the protection. You can check the Web Console for messages about blocked content.


You can check for problems with the sessionstore.jsonlz4 file in the Firefox profile folder that stores session data.

  • delete sessionstore.jsonlz4 and sessionstore.js

When sessionstore.jsonlz4 is deleted you lose pinned-tabs and open tabs and you will have to recreate them, so if necessary make a note or bookmark them. sessionstore.jsonlz4 is only present in the Firefox profile folder when Firefox is closed.

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.


You can create a new profile as a quick test to see if your current profile is causing the problem.

See "Creating a profile":

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.