Customizr causing balnk posts

Please read https://www.ads-software.com/support/topic/read-this-first-wordpress-5-0-master-list/

Thank you, Joy. The Classic Editor plugin worked, I can now edit my pages and posts. I guess the question remains do I have to change my Customizr theme, in order to function without this plugin?

If you have a theme question, you need to ask in the theme’s support forum.