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Cannot acces any website usinf Firefox - MS Edge works fine

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  • 1 has this problem
  • 1 view
  • Last reply by allemmon

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The following message occurs for all websites -

"Your connection is not secure

The owner of accounts.firefox.com has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website.

This site uses HTTP Strict Transport Security (HSTS) to specify that Firefox may 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"


"accounts.firefox.com uses an invalid security certificate. The certificate is not trusted because the issuer certificate is unknown. The server might not be sending the appropriate intermediate certificates. An additional root certificate may need to be imported. Error code: SEC_ERROR_UNKNOWN_ISSUER"

The following message occurs for all websites - "Your connection is not secure The owner of accounts.firefox.com has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website. This site uses HTTP Strict Transport Security (HSTS) to specify that Firefox may 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" "accounts.firefox.com uses an invalid security certificate. The certificate is not trusted because the issuer certificate is unknown. The server might not be sending the appropriate intermediate certificates. An additional root certificate may need to be imported. Error code: SEC_ERROR_UNKNOWN_ISSUER"

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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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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Thanks - problem seems have abated with disabling AVG HTTPS scanning