BizTalk Construct Message Error

See more:

biztalk

I'm putting together an orchestration that takes a message from the configured WCF receive location via the default pass-through pipelines, inspects some properties of the message and then constructs a response.

The orchestration is running because I can write to the event log out of it but I'm not getting a response, just timeouts. every time I test it the event log is filling up with messages like this:

"the message resource is present but the message is not found in the string message table"

and:

"System.InvalidOperationException: <OperationTriggerTransfer xmlns='http://tempuri.org' /> was not expected"

I'm using .net classes for my messages, and I'm not using schemas or maps yet. any ideas?