Hi Pavan,
Are you using ccBPM or NW BPM? Going for BPM is not suggested unless it is un-avoidable situation. In NW BPM we have
For your scenario, we can try using Multi-mapping, by having two source messages mapped to the single Invoice IDoc in the Message mapping?
One source message will have the MT of first file and second source message will have MT of 2nd file.
If you still want to go for the BPM approach, for the error you are facing you need to create Abstract interface consisting of Invoice IDoc structure and then use a transformation step to map the Abstract interface of IDoc with the Invoice IDoc and the use the send step to post the IDoc to the ECC system.
Regards,
Nitin