An unexpected error occurred while updating spanish class speed dating activity
it's a must when modifying data within the Grid View problem, for security reasons, I have Bind(include = some fields). Check that your Id and your Row Version are not null.for more information refer to this tutorial I also came across this error.This caused the error since N - 1 rows were affected due to the trigger deleting one of the child entities itself before entity framework tried to delete it.
The idea behind it is that you won't end up overwriting a change that your application didn't know has happened - it's basically a little safety measure thrown in by . If it's consistent, odds are it's happening within your own logic (EG: You're actually updating the data yourself in another method in-between the select and the update), but it could be simply a race condition between two applications.
From Paul Bellora's comment I had a similar issue but with a twist.
For me the issue was I didn't have the sql table setup correctly.
Edit: Unfortunately I am no longer at liberty to reproduce the problem I was having here, because I stepped away from this project and don't remember if I eventually found a solution, if another developer fixed it, or if I worked around it. That's a side-effect of a feature called optimistic concurrency.
Not 100% sure how to turn it on/off in Entity Framework but basically what it's telling you is that between when you grabbed the data out of the database and when you saved your changes someone else has changed the data (Which meant when you went to save it 0 rows actually got updated).
Are you able to view the SQL commands going to your database (EG: SQL Server Profiler for MSSQL)?