Are you not seeing a tab for the visual editor at all? The error that I am experiencing still shows a tab for it but you simply can not select it.
If you don’t see the tab for it at all you may want to make sure your enabled for the visual editor under your user account on the wp dashboard. I’ve read sometimes it has to be turned off and back on to work correctly. It may not be the solution but sometimes it is the simply thing we forget. Hope you get it this fixed soon.