You know how in wp 3.91 if you insert an image into the editor and if you click on the inserted image you get a pencil and cross icon that allows you to either edit or delete the image, well White Label CMS has a problem with that.
IF you define the name of an editor styling css into the respective setting of white label cms, this disables the cross and pencil icon as seen in the editor. I had "editor-styling.css" in that setting. When removed, the pencil and cross icon worked again. I was using the most recent version of the plugin at the time.