I get the issue when I try to customize the toolbar and save it as a preset. The editor works fine if using one of the default toolbar settings. But, when I go in and make changes, it technically should write a new XML file as well and reference that file for the toolbar settings.
Now, I do have all of the WA extensions installed. So, I may go back and explicitly uninstall both Form Builder and HTML Editor and reinstall to see if that will help.