I have a master page with a grid that inherits the form template from a content page. The fields are displayed correctly in edit and all valued but when I press update it says that the fields cannot be null.
This problem occurs only if the form template is on the content page while if you put the template directly on the master page then everything works.
I used a code similar to the demo https://demos.telerik.com/aspnet-ajax/grid/examples/data-editing/form-template-update/defaultcs.aspx as an example.
What I do wrong and how I can fix it?
ASPX Content Page
CS Master Page
ASPX Master Page