This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Cannot access gmail.com

  • 3 replies
  • 18 have this problem
  • 8 views
  • Last reply by callmeang

more options

I have been trying to access gmail.com for a couple of days and I keep getting this error:

An error occurred during a connection to mail.google.com. security library: improperly formatted DER-encoded message. (Error code: sec_error_bad_der)

I have downloaded chrome, which I do not like using, but I can at least access my gmail account with it. What do I need to do in order to fix this problem? I really don't want to stop using firefox all together, but if I cannot access my email, I'm going to have to.

I have refreshed, I downgraded firefox, I've cleared caches, I just cannot figure it out.

I have been trying to access gmail.com for a couple of days and I keep getting this error: An error occurred during a connection to mail.google.com. security library: improperly formatted DER-encoded message. (Error code: sec_error_bad_der) I have downloaded chrome, which I do not like using, but I can at least access my gmail account with it. What do I need to do in order to fix this problem? I really don't want to stop using firefox all together, but if I cannot access my email, I'm going to have to. I have refreshed, I downgraded firefox, I've cleared caches, I just cannot figure it out.

All Replies (3)

more options

Hello,

Try Firefox Safe Mode to see if the problem goes away. Firefox Safe Mode is a troubleshooting mode that temporarily turns off hardware acceleration, resets some settings, and disables add-ons (extensions and themes).

If Firefox is open, you can restart in Firefox Safe Mode from the Help menu:

  • Click the menu button New Fx Menu, click Help Help-29 and select Restart with Add-ons Disabled.

If Firefox is not running, you can start Firefox in Safe Mode as follows:

  • On Windows: Hold the Shift key when you open the Firefox desktop or Start menu shortcut.

When the Firefox Safe Mode window appears, select "Start in Safe Mode".

SafeMode-Fx35

If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, theme, or hardware acceleration. Please follow the steps in the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article to find the cause.

To exit 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 others with the same problem.

more options

I'm not entirely sure what fixed the problem, but when I went into safe mode, I was able to access it. So I went to the article and was going to restart firefox and start turning everything off to see what worked and what didn't, and it was working. Maybe some of the extensions just needed to be restarted or something - I'm not entirely sure! However, if it happens again, I know where to go, I didn't go to those articles first, and that's what was throwing me off.

Thank you so much! I can get chrome off my computer, haha.

more options

Well, I say it was solved, but it wasn't. It immediately did it again, and I have everything turned off now, I restarted in safe mode, and I can't get gmail. I can't figure out why, either. I can't think of what I've changed.