My stackoverflow question was closed so here's a blog post about CoreWCF

C# is not my primary language but have the misfortune of debugging C#/.Net junk.

Seems like an issue with not closing resources properly. Looking at your server code, seems the Close and Dispose methods are not overridden. Try that?

What resources do you think should or could be handled in an overriden close method on RandomService?

It'll be calling base.Close(), and doing what else?

"I dont know C# but ill make a bold assumption"