Since the 0.5 changes in TX-EDC regarding the endpoint data reference callbacks, there is the possibility that a transfer request is finished (and hence callback is invoked) before the actual transfer process state has been investigated and registered.
As-Should
Between starting of the transfer request and receiving the callback, a registration of the transfer process must be ensured.
As-Is
Since the 0.5 changes in TX-EDC regarding the endpoint data reference callbacks, there is the possibility that a transfer request is finished (and hence callback is invoked) before the actual transfer process state has been investigated and registered.
As-Should
Between starting of the transfer request and receiving the callback, a registration of the transfer process must be ensured.