Can log in to main page but cannot access any parts/forums using Firefox, my main browser (this via Chrome)
since midnight get error message saying some sort of security issue related to certificate???
I've had this sometimes with other sites where the certificate has not been updated - hence the cutoff at certain date/ time?
Are you aware of this issue?

I use Firefox, as well as other browsers from time to time with no issues.  Anyone else?

No problems with using Firefox here on this Forum..........
However, another (full size railway) site I am a member of has been flagged up as a security issue with Firefox since the end of last week, so I have to log in each time now, rather than staying logged in all the time. Perhaps Firefox have tweaked their security settings recently?

No problems here with Firefox on  2 laptops.1 desktop and Firefox mobile on my phone.

I'm reading this on Firefox right now and have no problems.

Ron

Still cannot access any content with Firefox - this is what I get

An error occurred during a connection to www.ngaugeforum.co.uk. SSL peer has no certificate for the requested DNS name.
Error code: SSL_ERROR_UNRECOGNIZED_NAME_ALERT

Firefox help Suggests an issue with your TLS???

Ah! Computers! Don't you just love them and they seem to be becoming self aware! I was shut out at midnight Monday and nothing I could do would allow the site. And then......seems to have righted itself??? Also had some problems with other trusted sites so I guess it was some sort of Firefox Security update conflict. Thanks for your assistance; much appreciated.

I ran into something like this some months ago. From what I managed to ascertain Firefox has taken upon itself to make a point about internet security and new versions prevent saved log in details automatically entering for non https sites. The certificate thing may be connected. I switched to using Chrome, and made it by default browser. Problem solved.