Try this please : https://support.mozilla.org/en-US/kb/what-does-your-connection-is-not-secure-mean and http://www.thewindowsclub.com/your-connection-is-not-secure-firefox and in case experience this one : https://support.mozilla.org/en-US/kb/troubleshoot-SEC_ERROR_UNKNOWN_ISSUER

Note : Firefox 56.0.2 is current release Note : Firefox 57 Quantum release date Nov 14th https://www.mozilla.org/en-US/firefox/quantum/ Note : Legacy Extensions will be disabled and or removed.

Please let us know if this solved your issue or if need further assistance.

Thanks folks They were the things I have already tried. But without success. You may be interested that the message even popped up when I tried to log back into Mozilla.

Note : Firefox 56.0.2 is current release May want to uninstall and reinstall from the Full Version Installer https://www.mozilla.org/firefox/all/

Please let us know if this solved your issue or if need further assistance.

Ok. What a nuisance as I suspect will loose my bookmarks. Interestingly, I can get to the download because the message pops up.

I will try getting there from IE

Is there a way to save all my bookmarks?

Your Profile should be saved as it is in a separate place. I just did this today myself.

If wanting to save a copy and should ( I have been using same bookmarks since Win95) Open Firefox Then from the Firefox Menu Bar --> Open Bookmarks --> Click Show all Bookmarks --> Click the Menu Import and Backup and Export Bookmarks as HTML

If Firefox does not change things can import them forever and they can be opened in any browser. I take mine on a usb key when travel.

Please let us know if this solved your issue or if need further assistance.

Hi Jan, on the error page, when you click the Advanced button, does Firefox show the code

SEC_ERROR_UNKNOWN_ISSUER

If so:

(1) Did you try disabling the Kaspersky feature to intercept encrypted connections as a test?

The steps in the support article weren't updated for the 2017 version, but that may mean they remain the same as the 2016 version: How to troubleshoot security error codes on secure websites.

(2) If Kaspersky is not the issue, could you share the certificate that Firefox finds objectionable?

Click the SEC_ERROR_UNKNOWN_ISSUER code and Firefox should display an encoded version of the problem cert. You can copy/paste that into a reply for a volunteer to decode and consider the Issuer information.

If you want to give it a try yourself, I use this site for decoding: https://certlogik.com/decoder/

Hi again helpful ones. I have been away from my computer for a few hours. Tried to log on to Mozilla support and I cant even do that.

jfisher2000 asked for the information. Here it is. This was a different message to earlier.

I have not reinstalled Firefox, but wonder if that's what is now needed. Thank you so much for patient help.

https://www.google.com.au/

Peer's Certificate issuer is not recognised.

HTTP Strict Transport Security: false HTTP Public Key Pinning: true

Certificate chain:

MIIGpDCCBYygAwIBAgIJALqIa0I8PIAZMA0GCSqGSIb3DQEBCwUAMCgxCzAJBgNV BAYTAkVTMRkwFwYDVQQDDBBRdXN0b2RpbyAoNDEwOTApMB4XDTE3MTAxNzEwMzAz NVoXDTE3MTIyOTAwMDAwMFowZjELMAkGA1UEBhMCVVMxEzARBgNVBAgTCkNhbGlm b3JuaWExFjAUBgNVBAcTDU1vdW50YWluIFZpZXcxEzARBgNVBAoTCkdvb2dsZSBJ bmMxFTATBgNVBAMUDCouZ29vZ2xlLmNvbTCBnzANBgkqhkiG9w0BAQEFAAOBjQAw gYkCgYEAsZMvzu2OmQ+SIh6BDMAicTzT2WeKoRvbLcn67LUnrXhgiXFUK9TefNB8 Wtjldi199zXletYSrObK92OXAW3P+ET3dzlDXZVcpKV+KNH74gASeE4fIXAdC/hK Jh1PzaQ7/7kLaBNsdteNwSjj2tgzUm+lBkCYV2n12xwLyofZ5ekCAwEAAaOCBBUw ggQRMIID4QYDVR0RBIID2DCCA9SCDCouZ29vZ2xlLmNvbYINKi5hbmRyb2lkLmNv bYIWKi5hcHBlbmdpbmUuZ29vZ2xlLmNvbYISKi5jbG91ZC5nb29nbGUuY29tghQq LmRiODMzOTUzLmdvb2dsZS5jboIGKi5nLmNvgg4qLmdjcC5ndnQyLmNvbYIWKi5n b29nbGUtYW5hbHl0aWNzLmNvbYILKi5nb29nbGUuY2GCCyouZ29vZ2xlLmNsgg4q Lmdvb2dsZS5jby5pboIOKi5nb29nbGUuY28uanCCDiouZ29vZ2xlLmNvLnVrgg8q Lmdvb2dsZS5jb20uYXKCDyouZ29vZ2xlLmNvbS5hdYIPKi5nb29nbGUuY29tLmJy gg8qLmdvb2dsZS5jb20uY2+CDyouZ29vZ2xlLmNvbS5teIIPKi5nb29nbGUuY29t LnRygg8qLmdvb2dsZS5jb20udm6CCyouZ29vZ2xlLmRlggsqLmdvb2dsZS5lc4IL Ki5nb29nbGUuZnKCCyouZ29vZ2xlLmh1ggsqLmdvb2dsZS5pdIILKi5nb29nbGUu bmyCCyouZ29vZ2xlLnBsggsqLmdvb2dsZS5wdIISKi5nb29nbGVhZGFwaXMuY29t gg8qLmdvb2dsZWFwaXMuY26CFCouZ29vZ2xlY29tbWVyY2UuY29tghEqLmdvb2ds ZXZpZGVvLmNvbYIMKi5nc3RhdGljLmNugg0qLmdzdGF0aWMuY29tggoqLmd2dDEu Y29tggoqLmd2dDIuY29tghQqLm1ldHJpYy5nc3RhdGljLmNvbYIMKi51cmNoaW4u Y29tghAqLnVybC5nb29nbGUuY29tghYqLnlvdXR1YmUtbm9jb29raWUuY29tgg0q LnlvdXR1YmUuY29tghYqLnlvdXR1YmVlZHVjYXRpb24uY29tggcqLnl0LmJlggsq Lnl0aW1nLmNvbYIaYW5kcm9pZC5jbGllbnRzLmdvb2dsZS5jb22CC2FuZHJvaWQu Y29tghtkZXZlbG9wZXIuYW5kcm9pZC5nb29nbGUuY26CHGRldmVsb3BlcnMuYW5k cm9pZC5nb29nbGUuY26CBGcuY2+CBmdvby5nbIIUZ29vZ2xlLWFuYWx5dGljcy5j b22CCmdvb2dsZS5jb22CEmdvb2dsZWNvbW1lcmNlLmNvbYIYc291cmNlLmFuZHJv aWQuZ29vZ2xlLmNuggp1cmNoaW4uY29tggp3d3cuZ29vLmdsggh5b3V0dS5iZYIL eW91dHViZS5jb22CFHlvdXR1YmVlZHVjYXRpb24uY29tggV5dC5iZTALBgNVHQ8E BAMCB4AwHQYDVR0lBBYwFAYIKwYBBQUHAwEGCCsGAQUFBwMCMA0GCSqGSIb3DQEB CwUAA4IBAQAzjZofQLOoZV4Nz+hK7ykwPHJcY33PlRDORBJbod2hd6xJJfLADFHE xDQsJP2zFi8aPsCHPwhVDSeb8pv1XZkW9Bgi/lS9U8JPklSgT3N+6JLvZhobOdX/ 6BkOEWsiextXgSRl3SssnF8C4SMyPFfb5DsEbTy8A2rtIobM/jK8x+WfmbU/Bs9h ozyPVAxHzDU6XrgzBdoNwRC8KHCvLhrygQ4BG1sCmGEjekq5e7I6bA26m9cWZ4QA wQF8W1v61OLZf5WndbeV5c9a0FMvqFbEnUHyeZpwA5miwjDFtiaDZrdZFwTy37/T 0hSm8vlBZDHnHMzUF3j3qr9k70aZazx/

Hello again Sorry people...I am at my wits end.

I have saved my bookmarks; uninstalled FF; reinstalled FF.

I turned off Kaspersky Do Not Scan encrypted sites.

The issue still exists.

I did check out the decoder but wasn't sure what to do once the certificate was checked.

Help please.... Jan

Hi Jan, thank you for the certificate, and apologies for the delay, we have a time difference, obviously.

I don't know what to make of this:

Issuer Name = Qustodio

Your connection appears to be intercepted by this "parental control" software: https://www.qustodio.com/

Does that sound like something you might have running on your computer?

Or possibly some impostor software is presenting itself as Qustodio.

Usually filtering software will update Firefox to trust it as an intermediary, but if you set up Firefox after that software, or use the Refresh feature, or create a new profile, then you might have to trigger the filtering software to do that again, or you might have to take manual action to do it. But I think the first question is whether Qustodio even sounds like something that should be there.

FABULOUS! Thanks you so much. You have found the issue. I have had that parental control software running for over a year as a protection for my grandchildren. Obviously a glitch has developed, but now I can work towards solving it. I disabled Qustodio and everything works.

I cannot thank you enough!

A brilliant service.

Jan