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I am not able to open google, youtube and facebook type major websites when i will to open it will show Error code: SEC_ERROR_UNKNOWN_ISSUER "

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  • Last reply by philipp

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I am not able to open google, YouTube and Facebook type major websites when I will open it will show Error code: SEC_ERROR_UNKNOWN_ISSUER "

How to troubleshoot the error code "SEC_ERROR_UNKNOWN_ISSUER" on secure websites

Your article will give only that particular antivirus solution information how to solve this issue, but what to do if I am using other antivirus software product like Quick Heal, Norton and other different antivirus which you have not mentioned in the article. I am using Quick Heal Antivirus Software. So please give me solution to solve this problem.

I am not able to open google, YouTube and Facebook type major websites when I will open it will show Error code: SEC_ERROR_UNKNOWN_ISSUER " How to troubleshoot the error code "SEC_ERROR_UNKNOWN_ISSUER" on secure websites Your article will give only that particular antivirus solution information how to solve this issue, but what to do if I am using other antivirus software product like Quick Heal, Norton and other different antivirus which you have not mentioned in the article. I am using Quick Heal Antivirus Software. So please give me solution to solve this problem.

Chosen solution

thank you - so apparently you have malware dubbed "my web shield" on your system that is intercepting all secure connections.

  1. please go to the windows control panel / programs and remove all toolbars or potentially unwanted software from there.
  2. then run a full scan of your system with different security tools like the free version of malwarebytes & adwcleaner, which are specialised in adware and browser hijackers.

Troubleshoot Firefox issues caused by malware

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All Replies (5)

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hi, a solution depends on the individual circumstances - so please give us more information about the error like shown in the screenshot by clicking on the error code, copying the text to the clipboard and then pasting it here into a reply in the forum.

thank you!

How to troubleshoot security error codes on secure websites

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I am attaching the file in which error have been mentioned.

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no, please don't attach a screenshot (nobody is going to transcribe that information from a picture), but copy/paste it in text form directly into a reply here instread...

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I am sending you a error mentioned in the page Your connection is not secure

The owner of www.youtube.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

www.youtube.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 https://www.youtube.com/


Peer’s Certificate issuer is not recognized.


HTTP Strict Transport Security: false

HTTP Public Key Pinning: true


Certificate chain:



BEGIN CERTIFICATE-----

MIIGljCCBX6gAwIBAgIRAJB2XTv8/mX8jESsTx+bpNwwDQYJKoZIhvcNAQELBQAw

JzELMAkGA1UEBhMCRU4xGDAWBgNVBAMMD015IFdlYiBTaGllbGQgMjAeFw0xNzA1

MjQxNzEzMDBaFw0xNzA4MTYxNzEzMDBaMGYxCzAJBgNVBAYTAlVTMRMwEQYDVQQI

DApDYWxpZm9ybmlhMRYwFAYDVQQHDA1Nb3VudGFpbiBWaWV3MRMwEQYDVQQKDApH

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TByWC87XVRxBBlIL5qFGH+0sHo8rj74MOJ7ig5cEpFAm5zMZOtBBkS/VwxolAgMB

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Emdvb2dsZWNvbW1lcmNlLmNvbYIYc291cmNlLmFuZHJvaWQuZ29vZ2xlLmNuggp1

cmNoaW4uY29tggp3d3cuZ29vLmdsggh5b3V0dS5iZYILeW91dHViZS5jb22CFHlv

dXR1YmVlZHVjYXRpb24uY29tggV5dC5iZTAMBgNVHRMBAf8EAjAAMB0GA1UdJQQW

MBQGCCsGAQUFBwMBBggrBgEFBQcDAjANBgkqhkiG9w0BAQsFAAOCAQEAzPbngBBW

qLJt1eiqSBZuQnRSo6Zs+O1PNZFyRqKU859HB7Fy01GGJFhl2oqb1SS4pbl7GmBM

tx6nX+rDBHaHvp1m+ccH3QuDhvqtyEeuauLn5zdHTx7No8UmSIrZ7u0t/YO23HFW

3NECSJRc5tIZTw/jrVyTj4SnUgcsZauJSsB3t4uKTRSzL0LP4EPcsEU+UrWPHp2d

+wO5yZ2eqDLS7HNvZqMi6Bwo/XQungPsezaUvD6vCfdGGVo5NWKREVvgBh5rJI/7

jQH2uT9uXBWacZ6kJfeKSExizO50j2b/+WXU53gdZgOVC+iquBlvH+E95zYXiG5G

wsacTmiE4eV5mA==


END CERTIFICATE-----
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Chosen Solution

thank you - so apparently you have malware dubbed "my web shield" on your system that is intercepting all secure connections.

  1. please go to the windows control panel / programs and remove all toolbars or potentially unwanted software from there.
  2. then run a full scan of your system with different security tools like the free version of malwarebytes & adwcleaner, which are specialised in adware and browser hijackers.

Troubleshoot Firefox issues caused by malware