Messages disappearing in BizTalk Server 2004 when the Envelope property of the schema is set to 'Yes'
It turns out that if your combine the normal XmlReceive pipeline with a Schema which has the 'Envelope' property set to 'Yes', the message is consumed, but never processed. It just vanishes into the void, no EventViewer error message or warning, no suspended message in HAT, nothing.
If you set the 'Envelope' property back to 'No' or '(Default)', things works as was to be expected. Ofcourse, setting the Receive Pipeline to a custom pipeline with the XmlDisassembler property 'Envelope Schemas' set to be the defined schema will split the interchange just fine.
However, I myself would expect at least a warning from BizTalk Server that it is consuming the message.
The message can be found to be parsed by the receive pipeline by looking in HAT from the 'Queries' menu / Most recent 100 service instances...