I have read several topics but can’t seem to find the proper solution for my problem. If I try to edit pages with Cornerstone, I get the following screen (in Dutch but I think somebody will recognize it): 
I have contacted the host and updated php to 7.2.15, cleared caches, updated all plug-ins, deactivated plugins, etc. but nothing seems to be working. Since I am not a professional, I really hope that someone can help me out here since my client would like to have some pages adapted, which I currently can’t do for him.
Thanks in advance! Regards, Karina
