From this morning I get this error whenever I access Google Docs and some websites. My system datetime is correct and I checked "Automatically from the Internet". My BIOS is OK. I cleared everything (cache, cookie, private data) in Chrome and restarted OS but nothing changes. How to fix it? Firefox works but Chrome has that problem.

The site's security certificate is not trusted!

You attempted to reach docs.google.com, but the server presented a certificate issued by an entity that is not trusted by your computer's operating system. This may mean that the server has generated its own security credentials, which Google Chrome cannot rely on for identity information, or an attacker may be trying to intercept your communications.

You cannot proceed because the website operator has requested heightened security for this domain.