I just changed theme from Human to Clearlooks and tried with your debug5: the upgrade process is getting several steps further now! Unfortunately it still became unresponsive a couple of steps later. Repeated attempts resulted in stop at same new place, see attached main.log.
I just changed theme from Human to Clearlooks and tried with your debug5: the upgrade process is getting several steps further now! Unfortunately it still became unresponsive a couple of steps later. Repeated attempts resulted in stop at same new place, see attached main.log.