While using a sniffing tool to see what is actually being sent from Biztalk to a receiving system can be a great way of learning whats actually being transmitted on the wire it took me a while to figure out why when removing the proxy address I kept getting error messages saying that I cannot have both proxy Address and “use default web proxy” set.
Setting “useDefaultWebProxy” to false resultet in:
“System.InvalidOperationException: This operation is not supported for a relative URI.“
Turns out that just deleting the proxy address in a Custom WCF port binding configuration isnt enough – you must acautally right-click the “proxyAddress” label and click on “Nullify “proxyAddress””.
The error can be detected by exporting the binding and check the configuration for the specific port, you will see “proxyAdress=”” ” in the binding indicating that the proxy is still configured – to an empty string, compare this with a port where you have never configured a procxy – the entry will not be present.