I’ve decided to write a short article about this annoying issue, because I’ve stumbled upon it twice during last month.
The user informed me that he’s unable to visit popular web sites like Google, because an warning message pops up on the screen informing him about certificates errors. Sometimes he could just add the page to the exception list, but sometimes he couldn’t do anything about the problem and just leave the page he was trying to access.
I’ve started my analysis by checking running processes, services and startup elements, because I was pretty sure that this kind of behavior is related with some malware residing on the workstation. I’ve upgraded the web browser, the anti-virus software, I’ve made some av scans but this didn’t give me an answer nor the solution to the problem, so I started to review the about:config configuration in Firefox in order to find some changes caused by some add-ons, but neither this solved the issue. Finally I’ve reviewed some Internet resources and found out that wrong system date/time may be causing this problem, so I’ve immediately checked the date setting on the workstation that I was working on and BOOM! The settings were incorrect despite the fact that the OS was set up to update the date/time automatically! I’ve updated the settings manually and this finally brought the solution to this issue!
I hope you’ll find this short article useful!