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Firefox updated today 65.0 and is now INTERMITTENTLY blocking all my sites

  • 6 replies
  • 4 have this problem
  • 9 views
  • Last reply by Sue L

Sue L
Sue L
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Message below is a Firefox message and is intermittent. Closing and opening Firefox will cure it for a while and then I am blocked again on next opening. Even your own links are showing with no HTML only text! I am having to close and reopen several times before I can get back to Facebook or Messenger or even MY BANK.

"Your connection is not secure

"The owner of www.facebook.com has configured their web site improperly. To protect your information from being stolen, Firefox has not connected to this web site.

"This site uses HTTP Strict Transport Security (HSTS) to specify that Firefox only connect to it securely. As a result, it is not possible to add an exception for this certificate.

"Learn more…

"Report errors like this to help Mozilla identify and block malicious sites

Message below is a Firefox message and is intermittent. Closing and opening Firefox will cure it for a while and then I am blocked again on next opening. Even your own links are showing with no HTML only text! I am having to close and reopen several times before I can get back to Facebook or Messenger or even MY BANK. "Your connection is not secure "The owner of www.facebook.com has configured their web site improperly. To protect your information from being stolen, Firefox has not connected to this web site. "This site uses HTTP Strict Transport Security (HSTS) to specify that Firefox only connect to it securely. As a result, it is not possible to add an exception for this certificate. "Learn more… "Report errors like this to help Mozilla identify and block malicious sites

Chosen solution

hi, this is likely your avast/avg security software tampering with encrypted connections. please either try to reinstall your security software or else follow the more specific steps for it at How to troubleshoot security error codes on secure websites.

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All Replies (6)

philipp
philipp
  • Moderator
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Chosen Solution

hi, this is likely your avast/avg security software tampering with encrypted connections. please either try to reinstall your security software or else follow the more specific steps for it at How to troubleshoot security error codes on secure websites.

Piterk
Piterk
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Probably some problems with certificates.

Sue L
Sue L Question owner
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philipp said

hi, this is likely your avast/avg security software tampering with encrypted connections. please either try to reinstall your security software or else follow the more specific steps for it at How to troubleshoot security error codes on secure websites.

Thanks - I have amended the settings in Avast but I am not marking this as solved until I have opened/closed Firefox (and my laptop) more times as this was intermittent on.

Sue L
Sue L Question owner
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Yes this seems to have done the job. Reinstalling Avast was not an option! Thanks Phillip

felipecerda
felipecerda
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Hi, I have Avast installed and I am getting the same issue. What is the correct setting to change in Avast?

Thanks, Felipe

Sue L
Sue L Question owner
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Felipe, this worked for me 

 Open the dashboard of your Avast or AVG application.
   Go to Menu and click on Settings > Protection > Core Shields.
   Scroll down to the Configure shield settings section and click on Web Shield.
   Uncheck the box next to Enable HTTPS Scanning and confirm this by clicking OK.

   In older versions of the product you'll find the corresponding option when you go to Menu > Settings > Components and click Customize next to Web Shield