After update fields missing and publish doesn’t complete

I installed the last update (3.0.18) and now all the form fields are missing – FYI, the form included a date field.

I also cannot add a new (complex) form as clicking publish loads the working animation and doesn’t complete.

Only the contact form still works (with 3 fields; name; email; message and submit). All of which CAN be put into a new form and published.