I've read lots of posts about this problem and tried everything suggested. This case is slightly different than the others. We have several people editing our website and we use several different devices - PCs, tablets, phone, etc.
It's only on one PC that the visual editor has quit working. On every other PC, tablet & phone the visual editor works fine. Which tells me it's got to be something on that PC but what?
We've tried clearing the cache & cookies on that machine. It doesn't work with either IE or Firefox. Two other wordpress blogs being edited on that same PC are fine. It's just the one website's visual editor. Of course the PC that this isn't working on is the person's who needs it the most.