User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36
Steps to reproduce:
I had several tabs open and went to "About Firefox" to update to version 65. After waiting to download to update, it was installed and I allowed the browser to restart.
Upon navigating to any website, I receive the message:
"Your connection is not secure
The owner of [ARBITRARY DOMAIN HERE] has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website."
The "Advanced" button shows:
"[ARBITRARY DOMAIN HERE] uses an invalid security certificate.
The certificate is not trusted because the issuer certificate is unknown.
The server might not be sending the appropriate intermediate certificates.
An additional root certificate may need to be imported.
Error code: SEC_ERROR_UNKNOWN_ISSUER"
The website should load normally. (I tried https://google.com/ and https://lobste.rs/).