Maybe it's too late, but I have found a workaround. You can convert the SourceId field to string before sending data. So your JSON data will look like.
The Default Model Binder is parsing all SourceId values as ints. But it seems . NET is missing a default type converter from int to long?.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.