Visual and Text tabs missing from Editor

Your problem could be one of 2 things:

  1. This could be because for some reason the tabs were disabled. To enable it log into your WordPress admin > WordPress Main Menu > Users > Edit(user with the issue) > First Option Top of Screen is “Visual Editor”> Unchecked the box > clicked save, and everything will be fixed.
  2. If 1 doesn’t work then it is most likely a conflict with either your plugins or themes. You can check this and locate the problem if you disable all plugins and turn them on one by one while checking to see which one is problematic. Also to see if the theme is causing the issue just pick some of the default wp themes.

I googled for some more information and this is what I found if you want to check for yourself link, link, link.