Try this : uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files , C:\Program Files(x86) & C:\ProgramData Then restart system. Then run Windows Disk Cleanup. (Note: This should be Pinned and run Weekly, If never done below expect 10's of gig's) Then run it again and click the button that says Cleanup System Files. Note: your Firefox Profile is saved. But you should make a back up before you do :

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles
• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer

Reinstall with Current Release Firefox 59.0.2 with a Full Version Installer

• https://www.mozilla.org/firefox/all/

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

Hi, thanks for your response.

The version installed is Firefox Quantum 59.0.2 (64-bit), so it is installed Program Files, not Program File(x86). It is a work computer that I just got. I cannot install or uninstall anything. Firefox was just installed yesterday. How do I fix this?

Hi, correct is installed but something maybe corrupted and that was why asked you to download a new full version installer.

The other way of doing things is not so much fun or easy :

fyi : There is security software like Avast, Kaspersky, BitDefender and ESET that intercept secure connections and send their own certificate.

• https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can
• https://support.mozilla.org/en-US/kb/firefox-and-other-browsers-cant-load-websites
• https://support.mozilla.org/en-US/kb/secure-connection-failed-error-message
• https://support.mozilla.org/en-US/kb/connection-untrusted-error-message
• http://kb.mozillazine.org/Error_loading_websites

SAFE MODE

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

In Firefox Safe mode these changes are effective:

• all extensions are disabled (about:addons)
• default theme is used (no persona)
• userChrome.css and userContent.css are ignored (chrome folder)
• default toolbar layout is used (file: localstore-safe.rdf)
• Javascript JIT compilers are disabled (prefs: javascript.options.*jit)
• hardware acceleration is disabled (Options > Advanced > General)
• plugins are not affected
• preferences are not affected

TEST''''is issue still there ?

Please Refresh but do this 1st: Delete your Cookies and Cache and TEST.

• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer
• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

then

• https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings

TEST....... If no issues then Extensions which need to be added back in 1 at a time and tested ..... Or it is your Profile : Make a new one and test ...:

• https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

If is your Profile :

• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile
• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Note: Any customization will revert back to default, you will also need to reinstall Extensions.

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

well, the first 2 links went to error pages. I cannot access this site on the work computer because of the issue.

I think I will just use chrome on the work computer.

Could you please provide detail about the issuer of the certificate?

• click the "Advanced" button show more detail
• click the blue SEC_ERROR_UNKNOWN_ISSUER message to show the certificate chain
• click "Copy text to clipboard" and paste the base64 certificate chain text in a reply

If clicking the SEC_ERROR_UNKNOWN_ISSUER text doesn't provide the certificate chain then try these steps to inspect the certificate.

• open the Server tab in the Certificate Manager
  • Options/Preferences -> Privacy & Security -> Certificates: View Certificates -> Servers: "Add Exception"
• paste the URL of the website (https://xxx.xxx) in it's location field.

Let Firefox retrieve the certificate -> "Get Certificate"

• click the "View" button and inspect the certificate

You can see detail like the issuer of the certificate and intermediate certificates in the Details tab.

Here it is: https://support.mozilla.org/en-US/kb/what-does-your-connection-is-not-secure-mean

Peer’s Certificate issuer is not recognized.

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

Certificate chain:

MIID+DCCAuCgAwIBAgIQdxfmEPSejqTxgehBF/KNvDANBgkqhkiG9w0BAQsFADCB rzELMAkGA1UEBhMCVVMxEzARBgNVBAgMCkNhbGlmb3JuaWExEzARBgNVBAcMClNh Y3JhbWVudG8xFTATBgNVBAoMDFN1dHRlckhlYWx0aDELMAkGA1UECwwCSVQxKTAn BgNVBAMMIGZvcmNlcG9pbnQucm9vdC5zdXR0ZXJoZWFsdGgub3JnMScwJQYJKoZI hvcNAQkBFhhwYXJrc2UxQHN1dHRlcmhlYWx0aC5vcmcwHhcNMTcwOTIwMDAwMDAw WhcNMTgxMDMxMTIwMDAwWjCBhjELMAkGA1UEBhMCVVMxEzARBgNVBAgTCkNhbGlm b3JuaWExFjAUBgNVBAcTDU1vdW50YWluIFZpZXcxGzAZBgNVBAoTEk1vemlsbGEg Rm91bmRhdGlvbjEPMA0GA1UECxMGV2ViT3BzMRwwGgYDVQQDExNzdXBwb3J0Lm1v emlsbGEub3JnMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAoATthEHh kqMLCHIIidByDiMqz/Vc0+9A56YcyR81J9dcduP+sDSfgpHzlgEKyi/+zTDeGwJ6 I1s/6fcEK2zcTKGUP7PSZq89i+TGDOB4HvwGS3pSrNzSR/mzqcIm0UsnWbMn9jK9 18S/VJle2cmzVWJYQ5LdrVdbhpnMj38h99w/jtGmMIAaNIXWfNEiaQTU2+W6wAW/ IOp7XInf+dK3mJmPWYNO0dJBWjDFjxfbMtYwnCo4mDLtC0AOJUADCb3T5fDOoNTs U9iNnJApWcBP0wjTmTZlG9p03vxT/Oh6NRHpQ0GrJzvsE873O13xPVNi6qCUsyX8 tWKLJ+nc0wyiewIDAQABozcwNTAzBgNVHREELDAqghNzdXBwb3J0Lm1vemlsbGEu b3JnghNzdXBwb3J0Lm1vemlsbGEuY29tMA0GCSqGSIb3DQEBCwUAA4IBAQC8Ptya jJ5qoHFWS9JNxUsuuoIfX3dNOCd67tLrD6uFLgM/MblLtM44JZLXxjQ+rhGDnu3W hFlQCxN38Zw3Z0cEttLkd47ikP9r0Q3HeZccZWS3XQ5ipDpGeXFwAGmybH18klMv Zq7sF35YhThitoMOxPuvglzVAWnisnfoeh2ASB7NYFCuU+qV+U8zivZP0OIBBxy/ 3B1s1NchYr2GcXs20X1P2d5oaocv2X+JgzgZpAqYjZsmD2XiVGW4VyNHZvRuFKto tpucyUipZtiVDyaKIh4FB8tQqIY5J55hTQ1ptuHr+SeW9N7tAJNwRCQFwo+FiD/r A+iaQq7NTCADGSL6

MIIEMzCCAxugAwIBAgIJANmPySrcnw3FMA0GCSqGSIb3DQEBCwUAMIGvMQswCQYD VQQGEwJVUzETMBEGA1UECAwKQ2FsaWZvcm5pYTETMBEGA1UEBwwKU2FjcmFtZW50 bzEVMBMGA1UECgwMU3V0dGVySGVhbHRoMQswCQYDVQQLDAJJVDEpMCcGA1UEAwwg Zm9yY2Vwb2ludC5yb290LnN1dHRlcmhlYWx0aC5vcmcxJzAlBgkqhkiG9w0BCQEW GHBhcmtzZTFAc3V0dGVyaGVhbHRoLm9yZzAeFw0xNzA0MTkxNDMzNDBaFw0xOTA0 MTkxNDMzNDBaMIGvMQswCQYDVQQGEwJVUzETMBEGA1UECAwKQ2FsaWZvcm5pYTET MBEGA1UEBwwKU2FjcmFtZW50bzEVMBMGA1UECgwMU3V0dGVySGVhbHRoMQswCQYD VQQLDAJJVDEpMCcGA1UEAwwgZm9yY2Vwb2ludC5yb290LnN1dHRlcmhlYWx0aC5v cmcxJzAlBgkqhkiG9w0BCQEWGHBhcmtzZTFAc3V0dGVyaGVhbHRoLm9yZzCCASIw DQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAMh+tvRRFaUV9oku+mbDlAfchvus cRB6FZ4++CqsKTHXcerhFFkdiQA6I6txY2Is1idu7MEehcsMfMnpo64ghehmYKK4 KCLpCJXiiKFxAml4voKY+1qhsei8sdbQzC7PQ2meGb8AHt3h74Rh0t2tCehCSmsJ /gmz1ffry9zgcULI+jC+Ojq2jPSzou6cez2TNK+UISDs53sF8iS4yLJiKWhvZgPS SqCnZBV6LrTGCGqq1GpfR3zJNe7JDF+MntlKoHjPy+cuMqRb5E4Mv1yWnyYvpkI5 vpsNrPSRcIAxHLisnsoZ2zF866N8Tex+QLHlQ3GGBiLdD0ehYZeqUkfrb1cCAwEA AaNQME4wHQYDVR0OBBYEFOqR2Kd/P9DyiR1WKMa0MRZGrR+nMB8GA1UdIwQYMBaA FOqR2Kd/P9DyiR1WKMa0MRZGrR+nMAwGA1UdEwQFMAMBAf8wDQYJKoZIhvcNAQEL BQADggEBAGbXg177907ynS+1ISKs0McdTA0/TeuVfrj6Kbhkpr90b9wA5pQmR2FP Gz/rUzCDn9d1K5aDRGbMOjnHEZeSHnaXjFcMTtdGa+1qJN9JhrBmMbNLexcHTj8p GQ5jJsL1vtolwJEXrTEs+YuODfJZPMnMf/T9kUSBKLh7r3h8tNQArg14YF/gOOfT 9H44/hKOTqVHgIPz73rd7vL3/4YS/u6KzRfp44ne25tbmVaD+TbiwXLZ/lqTTzLB k82uN2sEHARIiqjYw6tN7VncWIxfLlsgktrYNRpGvAzJw2ZevXxsHbN2nO2BXIwY jX97sEnXucZ7O1qZgYPWWmwF+KYmaXU=

The issuer is your Websense/Forcepoint security software.

Subject 	C=US, ST=California, L=Mountain View, O=Mozilla Foundation, OU=WebOps, CN=support.mozilla.org
Issuer 	C=US, ST=California, L=Sacramento, O=SutterHealth, OU=IT, CN=forcepoint.root.sutterhealth.org, emailAddress=parkse1@sutterhealth.org

I wonder why it works with chrome and ff?

Websense may be adding its root certificate to the Windows certificate store that is used by Google Chrome. Firefox uses it own certificate store (cert9.db, previously cert8.db).

You can export the root certificate in a browser that works (Google Chrome) and import this certificate in the Firefox Certificate Manager under the Authorities tab.

When prompted, place a tick on "Trust this CA to identify websites" trust bit to make the imported certificate work as a trusted root certificate to trust websites.

Note that trust bits should only be set for a trusted root certificate and never for intermediate certificates.

This is working now. I had to add both the forcepoint and websense certs to FF. Only 1 more question: How did you take the gobblygook from the cert I sent you and find out it was forcepoint and websense (in case I run into this issue again)

There are websites that can decode base64 encoded certificates.

• https://www.google.com/search?sa=N&num=100&q=decode+certificate

Thank you for your help!