Computer Learning

[Zorax]

This is firefox correct?
Could be a security issue.
Try this:
FF>Tools>Options
In the Advanced setting>Certificates>Select> 'Select one automatically' option

Also double check your system time and date. Sometimes because of savings time the time/date becomes wrong and certificates need correct time and dates.
As well as motherboard backup batteries dropping out making your system lose it's mind and time space continuum.