The site is giving "mixed content". You should be able to set your browser to accept mixed content and not complain about it. That would be the short term work around.

I'm on IE 11 and I have disabled asking me about accepting mixed content and everything seems to be working fine.

Now this doesn't mean this is the fix, it's just a work around.

Remember "mixed content" is what you're looking for. Oh mixed content means a mix of secure (https) and insecure (http) coming from this site. I'm slowly but surely tracking down the culprits.

Also access the site via https: