Nonce error!
I suddenly have the problem that I can’t make any changes to the entries in my acf post form. The point is that another doctor should be displayed in the frontend. When saving the new doctor, the message “nonce error” appears. I did this action every week without any problems.
Did someone build the site for you? Without knowing how it was built or the code that’s causing the error it going to be very hard for someone to help with this issue based on the information given.