System.Data.Linq.ChangeConflictException: Row not found or changed

I am trying to delete a selected gridview row using LINQ (No LINQDataSource).

When the selection is changed, the detailsview binding is changed also. I can add a new entry to the database, but when I added this code to a delete button inside the updatePanel, I got an exception:

try
{           
    var query = from i in db.QuestionModules 
                where i.QuestionModuleID == QuestionModuleID 
                select i;

    QuestionModule o = query.First();
    db.QuestionModules.DeleteOnSubmit(o);
    db.SubmitChanges();
}

This is the exception I get:

System.Data.Linq.ChangeConflictException: Row not found or changed. at
System.Data.Linq.ChangeProcessor.SubmitChanges(ConflictMode
failureMode) at
System.Data.Linq.DataContext.SubmitChanges(ConflictMode failureMode)
at System.Data.Linq.DataContext.SubmitChanges() 

I've had this problem for about a week, and no matter what I do, it is still there, and the record doesn't get deleted.

Any ideas on what to do?

OK - it looks as though (in my case at least) the answer was to set all non primary-key column's UpdateCheck property to Never in the DBML file. Doing this immediately cured the problem of "Row not found or changed".

Given the rumour that Microsoft are moth-balling Linq-To-Sql in favor of Entity Framework, one wonders whether these sorts of bugs will be fixed?

You are getting this error quite possibly because one of your fields has something different in the Linq To SQL designer and in the actual database.

In my case, it was because one of the fields was nullable in the database and not nullable in the designer, making it nullable in the designer as well solved the problem immediately.