TYPO3 Core

Updating a TYPO3 instance from 4.5.30 to 4.5.32, the RTE stopped loading and only showed the "Editor being loaded" screen.

Changing the following line helped:

RTE.default {
      # RTE can't load:
      #showButtons =  chMode, formatblock, insertcharacter, removeformat, unorderedlist, orderedlist, outdent, indent, link, copy, cut, paste, showhelp, about, pastetoggle, pastebehaviour, pasteastext, line, bold

      # RTE can load (added undo, redo):
      showButtons =  chMode, formatblock, insertcharacter, removeformat, unorderedlist, orderedlist, outdent, indent, link, copy, cut, paste, showhelp, about, pastetoggle, pastebehaviour, pasteastext, undo, redo, line, bold
}

I'm not sure if that's a bug or just a dependency between these buttons.
I think I originally disabled undo, redo because they had some issue back in the days. I hope re-enabling it is fine.