The relationship could not be changed because one or more of the foreign-key properties is non-nullable

Question

I am getting this error when I GetById() on an entity and then set the collection of child entities to my new list which comes from the MVC view.

The

Answer 1

I was face same problem when I am going to delete my record than some issue was occur , for this issue solution is that when you are going to delete your record than you missing some thing before deleting header/master record you must write to code for delete its detail before header/Master I hope you issue will be resolve.