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Hi. I keep getting this error message on Firefox, even trying to open help pages through Firefox.

  • 5 replies
  • 3 have this problem
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  • Last reply by naturemed

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fhr.cdn.mozilla.net uses an invalid security certificate. The certificate is not trusted because no issuer chain was provided. (Error code: sec_error_unknown_issuer)

fhr.cdn.mozilla.net uses an invalid security certificate. The certificate is not trusted because no issuer chain was provided. (Error code: sec_error_unknown_issuer)

Chosen solution

Thank you so much for your help. I actually figured it out. I delete the cert8 file and then restarted the computer and it seems to be working out.

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Check out why the site is untrusted (see the Technical details) and if this is caused by a missing intermediate certificate then see if you can install this intermediate certificate from another source.

You can retrieve the certificate and check details like who issued certificates and expiration dates of certificates.

  • Click the link at the bottom of the error page: "I Understand the Risks"

Let Firefox retrieve the certificate: "Add Exception" -> "Get Certificate".

  • Click the "View..." button and inspect the certificate and check who is the issuer.

You can see more Details like intermediate certificates that are used in the Details pane.

Please try clearing cache and cookies. Please also make sure that you date and time of your pc is correct as this may be the cause as well.

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Hi. I have clicked on understand your risks and then added an exception. Even after I have done this the pages are not loading correctly. I have reset firefox and I have also uninstalled and reinstalled firefox about three times and it keeps happening. The clock is also correct. This all started after getting the conduit virus which has been removed but that may have something to do with it.

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which version of Firefox are you using? go to Firefox/Help>About Firefox to check version number

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I'm downloading it directly from the Mozilla site so the newest version. I believe it says version 28.

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Chosen Solution

Thank you so much for your help. I actually figured it out. I delete the cert8 file and then restarted the computer and it seems to be working out.