So far I get the following error only when trying to go to
Https://www.Google.com ""SEC_ERROR_UNKNOWN_ISSUER" and it will not let me add an exception .
Additional System Details
- User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:58.0) Gecko/20100101 Firefox/58.0
Hi, please try : 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 :
Reinstall with Current Release Firefox 59.0.2 with a Full Version Installer
Please let us know if this solved your issue or if need further assistance.
There is security software like Avast, Kaspersky, BitDefender and ESET that intercept secure connections and send their own certificate.