BizTalk Server 2013 R2 EDI EDIFACT custom Target Namespace is not being used

Question

I have a client that has a partner that doesn't use the "out of the box" BizTalk EDIFACT 97A DELFOR schema. I'm using BizTalk Server 2013 R2.  I need to use a custom target namespace.  I have created a custom schema for EFACT_D97A_DELFOR with
a different namespace http://schemas.microsoft.com/BizTalk/EDI/EDIFACT/2006_<partnername>. 
In the Parties agreement/Transaction Set Settings/Local Host Settings, I have the following in a separate row under the "Default", UNH2.1=DELFOR, UNH2.2=D, UNH2.3=97A and TargetNamespace=http://schemas.microsoft.com/BizTalk/EDI/EDIFACT/2006_<partnername>
It wants to use the out of the box schema from the error below but I need it to use the custom schema. If I change the input file with a UH2.5 value along with changing the root node to match it EFACT_D97A_DELFOR_<UNH2.5), it works but the partner
will not be sending this, so it's not an option.
Error details: An output message of the component "Unknown " in receive pipeline "Microsoft.BizTalk.Edi.DefaultPipelines.EdiReceive, Microsoft.BizTalk.Edi.EdiPipelines, Version=3.0.1.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
is suspended due to the following error:
     Error encountered during parsing. The Edifact transaction set with id '' contained in interchange (without group) with id '000010080', with sender id '<senderid>', receiver id '<receiverid>' is being suspended with following
errors:
Error: 1 (Miscellaneous error)
70: Finding the document specification by message type "http://schemas.microsoft.com/BizTalk/EDI/EDIFACT/2006#EFACT_D97A_DELFOR" failed. Verify the schema deployed properly.
Error: 2 (Miscellaneous error)
71: Transaction Set or Group Control Number Mismatch
Error: 3 (Miscellaneous error)
29: Invalid count specified at interchange, group or message level
Any thoughts for this issue?
Thanks,
Sean

Answer 1

All,
Because the trading partner is not sending the UNH2.5, UNG2.1 and UNG2.2 values in the incoming message, the EDIFACT custom targetnamespace schema will not be used.  I created a decode custom pipeline component where I inject the UNH2.5 element,changed
the rootnode to the trading partner specific schema to  EFACT_D97A_DELFOR_XYZ (where "XYZ" is the value in the UNH2.5) and in the Party agreement->TransactionSetSettings->LocalHostSettings default row specifying the UNH2.1, UNH2.2
and UNH2.5, it will then use the custom schema(http://schemas.microsoft.com/BizTalk/EDI/EDIFACT/2006#EFACT_D97A_DELFOR_XYZ.  I could've injected the UNG segment
and used a custom target namespace and not changed the rootnode of the custom schema but didn't want to add all that extra segment information.
The example below assumes that the UNH segment only has values "up to" UNH2.4 only and appends the UNH2.5.  Uses the UNA segement to dynamically set the componentDataElementSeparator.
//UNA segment e.g. UNA:+.? '
//this example above has ' as the segmentTerminator, : as the componentDataElementSeparator, + as the dataElementSeparator
string unaSegment = messageBody.Substring(0, messageBody.ToUpper().IndexOf("UNA") + 9);
string componentDataElementSeparator = unaSegment.Substring(3, 1);
string dataElementSeparator = unaSegment.Substring(4, 1);
string segmentTerminator = unaSegment.Substring(8, 1);
string UNH_Segment = messageBody.Substring(messageBody.ToUpper().IndexOf("UNH"));
UNH_Segment = UNH_Segment.Substring(0, UNH_Segment.IndexOf(segmentTerminator));
//inject UNH2_5 in the existing UNH_Segment
messageBody = messageBody.Replace(UNH_Segment,
UNH_Segment + componentDataElementSeparator + UNH2_5);
Thanks All for all your help!!
Sean Boman