Entity Framework no InsertFunction element exists

because it has a DefiningQuery and no InsertFunction element exists in the ModificationFunctionMapping element

most likly: No primary key defined => EF treats Table as view and generates read only code

I had to remove the DefiningQuery Element in the .edmx File and also I removed the store: 

like described here:

http://stackoverflow.com/questions/15322894/because-it-has-a-definingquery-and-no-insertfunction-element-exists-in-the-mo