Idoc error for TU creation in EWM from S/4 Shipment

[AmitG]

Hi SAP experts,

I have embedded EWM 1909 version. The process that we are trying is to create TU in EWM from Idoc with reference to shipment in S/4.

The Idoc settings are done, SPRO config is in place. However, every time I create shipment, the Idoc fails, the latest error is 

"Reference is not found for ERP delivery 18*** from system DEVCLNT***"

Let me know please what fix is required to get TU created in EWM?

Regards,

Amit G.

[Daniil]

So as it is written in the error message you need to distribute the delivery. If it is distributed, check smq2 maybe it stucks there