Hi Salesforce Product Team. Could I ask for assistance on case 21657875? I am seeing application errors in the lightning app builder after Spring 19. The error occurs if you are editing existing pages or starting brand new "home page" options in lightning app builder. The error presence is immediate and appears 30 seconds after the page is loaded in the app builder. I also see the exact error if i start off with a brand new blank page with no components loaded.

Is anyone else seeing this behavior? It seams pretty serious because it affects home pages assigned to profiles or any new page created in platform after spring 19 before it is saved or assigned to users