Hi Carlton
From the Log Viewer, it looks like when the web service is accessed from PI, the response is not CData-wrapped which differs from it's behavior when accessed by SOAP UI.
Anyway, that is besides the point, since Praveen has been assisting you based on that non-CData structure.
I think you are not far from resolving this and I encourage you to persevere as Praveen is providing you very good assistance. I won't provide you with anything specific at the moment since Praveen is already guiding you, but I will give you some general pointers. If you approach this issue one-step at a time, you will eventually get there.
At the moment, it looks like you are stuck with the message mapping after extracting the inner XML using XSL. The error is most likely because the input data does not match the source structure expected by the Message Mapping.
The few tips I'd suggest are:-
i) Use MessageLoggerBean as mentioned above in the receiver channel to log a version of the response payload
ii) Use this response payload and run through the OM one-step at a time. This way, it'd allow you to see the output of each step, i.e. output after XSL, output after MM. The output of each mapping step of the OM will be the input to the next step. You can select which step(s) of the OM is/are executed as shown below.
iii) Check that the output of the XSL step matches the input structure of the MM step
If there is a mismatch, you'd see that the icons are red as shown below.
Regards
Eng Swee