Unable to browse messages sent via Python client

The UI reports a NullPointerException and does not browse the messages when sending a message via our Python client. The error, displayed on the HawtIO console is:

Operation browse() failed due to: java.lang.NullPointerException

This problem does not happen with other clients. However I could not identify the precise reason why the HawtIO UI throws this error only for the Python client.

I attached a packet dissection for C amq-c-proton.txt (which uses Qpid Proton and don't cause the problem) and the Python amq-python.txt (which also uses Proton, but is triggering this problem). There are some differences, but I don't think either should cause this problem.

The raw packages, as provided by Qpid Proton debugging support are also attached.