When creating a new ADO.NET Data Service you may find yourself with this error.

Don’t call it quits on ADO.NET Data Services because of this error. It is very easy to fix. Have a close look at the code generated by Visual Studio for you.

Here the code calls SetEntitySetAccessRule on “MyEntitySet” but most likely your entity set is not called “MyEntitySet”. Similarly the second line sets operation access rule again on “MyServiceOperation” and you may want to set access rules on your operations. If you want to include all operations and all entity sets in the two method calls you can simply specify “*” as the value for first parameter.