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Gmail not loading in Firefox 99.0.1

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  • 2 have this problem
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  • Last reply by cor-el

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I have had a problem with Gmail since yesterday April 13, which was the same day my browser updated to 99.0.1. I'm using a Windows 10 machine.

Gmail is displaying the "Oops… the system encountered a problem (#001)" error message and will not load my inbox. Other websites in Firefox load fine (including other Google apps like Drive and Calendar), and Gmail works fine in other browsers.

I have had a problem with Gmail since yesterday April 13, which was the same day my browser updated to 99.0.1. I'm using a Windows 10 machine. Gmail is displaying the "Oops… the system encountered a problem (#001)" error message and will not load my inbox. Other websites in Firefox load fine (including other Google apps like Drive and Calendar), and Gmail works fine in other browsers.

All Replies (3)

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Hello! You can try clearing browser cache: Clear your cache without clearing your browsing history You can also try clearing site cookies: Clear cookies and site data in Firefox (Note that clearing cookie/s of Gmail might remove your login, which means that you might need to login again into Gmail after clearing website cookie/s)

Modified by -elison-

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Hi Elison -

I did try clearing my cache and my cookies, which did not solve the problem. Oddly, using Firefox in private browsing mode does work fine.

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You can remove all data stored in Firefox for a specific domain via "Forget About This Site" in the right-click context menu of an history entry ("History -> Show All History" or "View -> Sidebar -> History").

Using "Forget About This Site" will remove all data stored in Firefox for this domain like history and cookies and passwords and exceptions and cache, so be cautious. If you have a password or other data for that domain that you do not want to lose then make sure to backup this data or make a note.

You can't recover from this 'forget' unless you have a backup of involved files.

If you revisit a 'forgotten' website then data for that website will be saved once again.

If clearing cookies didn't help then it is possible that the cookies.sqlite file in the Firefox profile folder that stores the cookies got corrupted.

  • rename/remove cookies.sqlite (cookies.sqlite.old) and when present delete cookies.sqlite-shm and cookies.sqlite-wal in the Firefox profile folder with Firefox closed in case cookies.sqlite got corrupted.

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