Internal Validation error in ECC

Hello Experts,

I am working on a PO collaboration scenario. The system landscape is ECC-PI-SCM

While creating ASN it’s getting published which means  internal validation is done and is correct in SCM server.

Note: I have maintained both customer BP (NA01) and also vendor BP(SKINT) properly in SNC.

As the DDN is reached successfully in ECC ( as shown by a checked flag) so I think the error is in ECC side. It seems there are some internal validation done in ECC side. Can anyone please explain internal validation done in ECC for ASN process.

Thanks & Regards

Pratyusa