Dehydrated basically means that Biztalk has put your orchestraiton to sleep waiting on a response (i.e. it’s memory is written to a database). When it wakes up, we say that it is rehydrated.
What causes dehydration? Usually a Receive statement or maybe a Delay statement (I’ve heard it happens after 2 minutes, but that is just a guess).
Sounds like you might have a correlation issue. The \”delivered not consumed\” means you probably sent a message out and then followed up with a receive to get it back. If the correlation doesn’t match up, the Biztalk receives the message back, but doesn’t know who to give it to (i.e. which orchestration). Use the free BTSSubscriptionViewer included in the Biztalk developer tool or SDK directory. This will show you what your orchestration is correlating on.
So since the message was delivered/not consumed – your orchestration probably is probably sitting on a Receive statement and is still waiting for a proper response.