hi, first please make sure that the date, time & timezone are set correctly on your system. if this doesn't solve the issue (or it is already set properly), a solution depends on the individual circumstances:

• what is the error code shown when you click on advanced on that error page?
• please also give us more information about the error by clicking on the error code, copying the text to the clipboard and then pasting it here into a reply in the forum like shown in the screenshot.

thank you!

Hi Thanks for your very prompt response. There have been no changes to date and time etc. Here below is a screenshot typical of the response I receive from every site I now try to contact.

The two additional screenshots are for a different site.

Mike

thanks, we'd need to have this information from the 3rd screenshot in text form to know what's going on though - please use the dedicated "copy text to clipboard" button, as transcribing all that would be too much work :))

Try to copy the cert9.db file from the "Old Firefox Data" folder on the desktop to the current profile folder with Firefox closed to recover all certificates.

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

I can press the Copy Text to Clipboard button, but don't see the text anywhere so how do I send it to you?

after clicking the "Copy Text to Clipboard" button, you can paste it here into the reply box on the forum by pressing command+v.

Hope this helps:

https://www.google.com/search?q=moodyowners&ie=utf-8&oe=utf-8&client=firefox-b-ab

Peer's Certificate issuer is not recognised.

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

Certificate chain:

MIIDqTCCApGgAwIBAgICHsMwDQYJKoZIhvcNAQELBQAwaDELMAkGA1UEBhMCQ1ox DzANBgNVBAgTBlByYWd1ZTEOMAwGA1UEChMFQVZBU1QxHTAbBgNVBAsTFFNvZnR3 YXJlIERldmVsb3BtZW50MRkwFwYDVQQDExBBdmFzdCB0cnVzdGVkIENBMB4XDTE4 MDgyMTA4MDUwMFoXDTE4MTExMzA4MDUwMFowaDELMAkGA1UEBhMCVVMxEzARBgNV BAgMCkNhbGlmb3JuaWExFjAUBgNVBAcMDU1vdW50YWluIFZpZXcxEzARBgNVBAoM Ckdvb2dsZSBMTEMxFzAVBgNVBAMMDnd3dy5nb29nbGUuY29tMIIBIjANBgkqhkiG 9w0BAQEFAAOCAQ8AMIIBCgKCAQEApWM+l3jZeyEHyrLuZi4gIbkIy0IHUrqvyp7x 4XYG3zWvqpem1COWHz9a3akz2nPH1sWshmVOAhco+t39wG7lmbKHnwKWnheMUfno CSaPNDZd6svxLNJdeGvEQFSrMww1vkAop0+ImUtEDYx7EHwjA80p6bgb1Mo2WrJg V2es8/3ZIFyOSsq+RuEFM18Hvzfyr6aBlcKlWM21xA4424wQ19rRzCsCvOG9EYL3 YSgLgRd5Yyau6xmwNwMpQfZd0r+eBONzpN5fvm+Zo39PwOIe4nOSClqzqZL1Mw+1 jwW5wEui81lIBAldZB2WkXO9OYA1QM6o5UyXAvmC8uuKrCxo2wIDAQABo10wWzAd BgNVHQ4EFgQUNX2XMf16WI4dsiBYmg3JiZMZNyMwHwYDVR0jBBgwFoAUeOnL9tvK bKd1VCxzzWTmyIzuu4QwGQYDVR0RBBIwEIIOd3d3Lmdvb2dsZS5jb20wDQYJKoZI hvcNAQELBQADggEBAJnX/1Obvu0UKmHieZVa9f0Ve3EIp4zytyM/QMp258HvqT6b VtFz8Sz8VAcnqjpp/3d/pnyGQFUV8SltLhLKQdMHyhZ26NmRY8Z5d43Kk6uQ460t 5qZ05+qsSrFnE08sYtlLwdp9eSo6m6zsLOWeEVop8nlygcW9v+dHTHTw3sEMSCI3 cb5tftQz+RUCynjV7qisF8zO4ufvvIp0ROLRhSem3/GR/MSwvy/hlFMu6GU/XnBj CAbksCROP4qJ6FGgLLQCsqq/zoXcvtFs1eK06Jb/oJVC84SLj6Vi15/BdP7bcUTw QaUwAs70vxSQBVbBYuj4vkrdHLymqp5n/YNhSwI=

thanks, so it appears that the avast/avg software on your system is tampering with secure connections. you should try disabling https scanning in its webshield settings like described here: https://support.avast.com/en-ww/article/189/ (instructions are for windows, but i think it should be fairly similar on osx)

That did the trick. Thank you for your help.