I was using the TCP adapter to allow the mainframe folks to query SAP for pricing info and get a response back.  But there was a problem – somewhere.  The TCP connection?  The message?  I was having a dickens of a time finding out where the error really was.

Then there was the orchestration where there was that red bang (!) that indicated an error.  However, the expression did not have any error, plus the orchestration built and deployed okay.  Of course, the application would fail – somewhere!.  Tracked the error down to something to do with the response message to the TCP adapter.

Very frustrating and another BT developer kept telling me that the red bang was meaningless, because BT was ‘flakey’.  Besides, when I used the TCP Adapter test harness the message would go through without an error!  So, that would tell you that it wasn’t BizTalk, but something with the TCP connection, right?

 But that red bang in the Message Assignment shape just annoyed me to no end, even though there wasn’t any error in the expression.  Finally, and I don’t know exactly what I did, I changed some parameter in the expression and it was underlined and was in error (for finally the 1st time!).  Reading the foot of the dialog, it read that a reference to the Microsoft.BizTalk.Pipline.dll was missing.  What?  That was there (I thought) – quickly checked references and found I had the other references but not that particular one.  Added it in and no more red bang, plus the orchestration now worked.

Why this error didn’t manifest itself to start with – I just don’t know, but sure wasted a lot of time trying to track down where I’d gone wrong with the message, or the pipeline or the flat-file or the TCP connection or the orchestration, etc., etc.