Appointments+ Adding new one in backend hangs

Hi there,

I have recently updated Appointments+ 2.0.5 to 2.1.0. Also, Worpdress updated to 4.7.5.

Ever since, when I try to add a new appointment in the backend, the wheel keeps spinning and nothing happens. when I refresh the page, it didn't add anything.

What info do you need to be able to help?