I’m working with a custom WCF adapter, and now we get some issue when pipeline failed validation : here is the MSDN explanation to handle it
For a receive location, you can configure one of two error handling options under the Error Handling section on the Messages tab in the Transport Properties dialog box.
If the Suspend request message on failure option is selected, the incoming request message will be suspended should there be a processing failure in the receive pipeline or a failure in the routing of the message. This allows the sender of the message to succeed in their transmission to BizTalk Server and receive an acknowledgment (ACK) message. BizTalk Server will suspend the message and record a complete error record for the failed message. However, it also does not send the message exception back to the sender in this case. This applies to one-way ports only and will send an ACK if checked, and if unchecked will send a NACK. For two-way ports, if processing fails, BizTalk will always receive a NACK.
However, if the client needs to have access to the failed exception, select the Include exception details in faults option. When selected, this returns a SOAP fault to the caller if a processing error occurs. This is the same as specifying the serviceDebug behavior with “IncludeExceptionDetailsInFaults” to True on the Behavior tab of the WCF-Custom or WCF-CustomIsolated adapters. The detailed exception is now sent to the client. This option is more practical and safer to use during development of an application than in production because the internal fault messages most likely should not be sent to callers of the service.
For the two-way send port, you can choose whether to forward SOAP fault messages on to the original caller over a solicit-response send port by selecting Propagate fault message. If this option is not selected, BizTalk Server will generate a NACK first, and then suspend the message. If it is selected, BizTalk Server will treat the message as a valid WCF response message from the external service and the response message will not be suspended because it is propagated.