Large WCF web service request failing with (400) HTTP Bad Request

Question

I\'ve encountered this apparently common problem and have been unable to resolve it.

If I call my WCF web service with a relatively small number of items in

Answer 1

It might be useful to debug the client, turn off Tools\Options\Debugging\General\'Enable Just My Code', click Debug\Exceptions\'catch all first-chance exceptions' for managed CLR exceptions, and see if there is an exception under-the-hood on the client before the protocol exception and before the message hits the wire. (My guess would be some kind of serialization failure.)