Customize Form not working ERPNext: v7.2.12

Hi,

Trying to use customize form after update. Neither “Refresh Form” nor adding new field works. Getting Fade screen after trying to update the change or referesh form. Facing same issue on two different installs, is any one else also facing this issue?
Installed Apps
ERPNext: v7.2.12
Frappe Framework: v7.2.10

Can you share a trace?