Cannot connect to App Store and Chrome problems with your connection is not private
I have a MacBook Air OSX Version 10.8.5. I have Chrome Version 42.0.2311.135 (64-bit).
Please tell me what I should do to fix this and whether it is a sign of problems or a compromised computer.
Very often when I go to a site I get a Privacy Error when visiting most sites (including Twitter, Apple discussions, support and product site). The screenshots are below.
Sometimes I can bypass the warning and sometimes I can't. Based on suggestions from friends this is what I've tried. This also may be relevant to an issue with certificates.
Is it because all these sites have sha-1?
https://garage.godaddy.com/webpro/security/google-chrome-phasing-ssl-certs-using -sha-1/
I deleted some login and system certificates that were expired or had red x's. I tried to delete the system root Keychain certificates but I don't see any options to delete them.
I also looked at the Proxies window, There were two entries under Bypass Proxy Settings and I deleted them. One was *local and another was a address number.
I've restarted a bunch of times, started in safe mode, and ran Disk Utility to verify and repair disk. Both showed no problems. I really appreciate your help and suggestions.
I have thought about upgrading the OS, if it would help, if it would provide extra security. Now I can't access the App Store to try that.
MacBook Air, OS X Mountain Lion (10.8.5), null