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Why is Gmail unstable on Firefox?

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For two days now Gmail has been unstable on Firefox. It keeps displaying this message: "Oops - The system encountered a problem (#001)".

While in that state, the send messages folder is empty, and I can't attach documents to an email.

Google suggests clearing the browser cache and cookies. Don't want to do that - much work required to recover.

For two days now Gmail has been unstable on Firefox. It keeps displaying this message: "Oops - The system encountered a problem (#001)". While in that state, the send messages folder is empty, and I can't attach documents to an email. Google suggests clearing the browser cache and cookies. Don't want to do that - much work required to recover.

All Replies (5)

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Did you try Firefox in Troubleshoot Mode?

Works for me and I'm able to attach a file. see screenshot

Helpful?

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That didn't fix it - but thanks for the suggestion. That's one of Google's recopmmended steps.

Helpful?

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Window home or pro? What security software are you running?

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You can try these steps in case of issues with webpages:

You can reload webpage(s) and bypass the cache to refresh possibly outdated or corrupted files.

  • hold down the Shift key and left-click the Reload button
  • press "Ctrl+F5" or press "Ctrl+Shift+R" (Windows,Linux)
  • press "Command+Shift+R" (Mac)

Clear the Cache and remove the Cookies for websites that cause problems via the "3-bar" Firefox menu button (Settings), click the padlock icon (Clear cookies and site data) for the domain in the selected tab.

"Remove the Cookies" for websites that cause problems:

  • Settings -> Privacy & Security
    Cookies and Site Data: "Manage Data"

"Clear the Cache":

  • Settings -> Privacy & Security
    Cookies and Site Data -> Clear Data -> [X] Cached Web Content -> Clear

Start Firefox in Troubleshoot Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or if userChrome.css/userContent.css is causing the problem.

  • switch to the Default System theme: "3-bar" menu button or Tools -> Add-ons -> Themes
  • do NOT click "Refresh Firefox" in the Troubleshoot Mode start window

You can check for issues with Enhanced Tracking Protection and Total Cookie Protection. 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.

  • click the shield icon for more detail and possibly disable the protection

You can check the Web Console for relevant-looking messages like about blocked content.

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This could be a problem with the TLS 1.3 Early Data feature also known as Zero Round Trip Time Resumption (0rtt). You can try to set security.tls.enable_0rtt_data => false in about:config to disable this feature.

See also:

Helpful?

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