The latest patch level is 50 and you are on 26 for kernel 741.
Have you tried with that patch level ?
If you reset the upgrade then you will need to start all over again. Moreover there is no need to reset the upgrade if you don't know where the problem is and when you are not sure how to fix it. You will end up in the same state in the next execution.
If the background job is failing then check the work process trace file.
Try to restart the system and repeat the phase in SUM.