There is some sort of database validation happening preventing you from writing the data into it.
The solution is already stated on this page:
Validation failed for one or more entities. See 'EntityValidationErrors' property for more details
As an extra note to this as you are using .net mvc you should use System.Diagnostics.Debug.WriteLine() instead of Console.Writeline() and this will write to the debug output window when you are debugging. As you cannot write to the console when running a mvc project.
