I have been pulling my hair off since last night because I could not see the content of pages in visual editor, in text mode every thing was visible. I tried on 3 computers at home. searched in the Q and A area. went to Live chat but I could not fix it, by any of the ways. Finally I sent a support ticket. But the support said my visual editor is working fine in their end so try clearing the history and Local DNS cache. Oh how on earth I am suppose to do that? so finally found the answer in the good old google. Here are the steps I took so you do not have to pull your hair off.
PS: Clearing the history and the local DNS cache also did not work. Untill I Forced load the editor as in page 4. I think I got this problem after installing TinyMEC Advance plugin because someone in Live Chat told me he had the same issue after installing this plugin.
But I'm bookmarking this training, in case I have to go the extra mile(s) like you did, thanks a bunch!