Visual Editor on my site will not function

When I just attempted to start a new post, I could input the post title and add in categories and tags. But aside from the two plugins I use, the Visual Editor toolbar is completely missing. And I am unable to type anything into the editor. Switching over to Text Editor is hit and miss (sometimes it will load, but most of the time it will not).

I’ve tried this in several different browsers (Safari and Chrome) with the exact same problems. Please advise?