This is the 1st time I meet this.
Normally when we received an inbound X12 file. A 999 will always be generated (by configuration in BizTalk) and in case of interchange level error occurs, a TA1 will be created.
But today I got a X12 file with some formatting errors, the error popup in BizTalk is :
Delimiters are not unique, field and component seperator are the same.
The sequence number of the suspended message is 1.
I am expecting to have a 999 or TA1 generated to reject the inbound file. but none of these 2 files created.
My question:
You should definitely not expect a 999 (which would be transaction set specific), because this error prevents BizTalk from parsing the transaction set at all - it doesn't have a reliable way to determine what kind of transaction it is.
A TA1 could be appropriate, but this seems like a grey area - might be worth contacting Microsoft support about. The documentation indicates that an invalid ISA should result in a negative TA1, but the error codes for TA1 don't list this particular scenario as one that's support (or at all).
A possible work around would be capturing this kind of message, generating a TA1 for it, and routing it back to the TP. However, having non-unique delimiters may make it impossible to determine the TP from the message itself, even though you might be able to determine it from context (but maybe not if multiple trading partners use the same ports/locations). My guess is that's why BizTalk isn't handling it properly out of the box. To be honest, unless this happens fairly frequently it'd probably be easier/more realible to deal with it on an exception basis with human intervention.
As far as capturing the message, I'm thinking you'd need a custom pipeline component - perhaps even subclassing the EdiDisassembler so you can catch this particular exception and deal with it.