Error 500 When opening "Contacts"

[TomV]

Oh -oh ... We removed a custom field from Contacts. And seriously regret as now we can not open any contact. Going to https://espo.mysite.com/#Contact Gives a red Error:500 in the top

What to do? Where to start????

[TomV]

Ok, strike that. The Error 500 disappears after carefully removing any reference to that field from any layout. Save and refresh each layout page. And Ctrl-F5 the Contact list.