foreach (var item in order.MyFiles)
{
var newFile = adapter.db.File.CreateObject();
newFile.Name = item.FileName;
adapter.db.File.AddObject(newFile);
adap
This could be because of a cyclic reference in you EDMX back to the same table.
Means for example if EmployeeDepartment is the table that you are going to update and the Primary key is EmployeeDepartmentID and if it is identity column and auto-generated, Check in the EDMX whether the EmployeeDepartmentID is referenced back to itself. If so, right click on that foreigh key reference and click delete.
This worked for me and I hope this works for you as well.
Thanks,
Bibin.