I had a similar problem of not being able to access some sites I used regularly. It would put them in the header bar but only display a white screen, if I right-clicked on the page and viewed the source it would show me the text etc, so it was accessing the site, not displaying it.
I used anonymouse.com and put in the site web address and it displayed fine, so it was some sort of personal settings problem.
I updated my antivirus, uninstalled and reinstalled Java and Adobe Flash (maybe some other bits that also auto-updated), powered off and back on and it was ok.
This was after I’d deleted History, cleared caches and passwords, lowered security settings etc, which had no effect.
Might work, might not.