Recently when editing in Pro's Content Builder the graphics of the sections and elements don't show. They are there because on the front end all is well (thankfully as that is most important), they just don't show up in the editor (see attached images).
See the site itself as to how it really (should) look(s): http://blenckerspersonaltraining.nl. When clicking on the settings of an element it usually reverts back to the proper view but only per section/element. As I said the front end is alright but it is rather confusing when editing and not seeing what happens.