AVG blocking Facebook

AVG is preventing me from getting on Facebook. I discovered last night if I shut down AVG I can get on Facebook. When I turn it back on I can't. I have added Facebook to the exception list but that didn't help. 
I get the warning "This site is not secure" then, there is a link to go to my start page. Below that, is says "The website's security certificate is not secure Error Code: 0"Can you help me fig out what to do to fix this issue? I have a screenshot of the error message but don't see how to post it here.
Thanks, Regards, Eric Storck