I think I would try that better 5V 4A supply like Rastus suggested, just by itself, no USB hub, first.
You might need an adapter to go from a typical barrel plug to micro-USB, or a supply with both. Cheap USB hubs can be troublesome too, and good ones are not cheap, by a longshot. Look at the cable Western Digital is selling with their Pi drives (not my favorite, but as an example of what it takes to get an older HDD to work, if that is what you have).
My Western Digital WD10JMVW 1 TB drive works fine using either one of the two "stronger" 5v 2A power supplies I have (same drive as in a Passport). So does the WD5000LPVX with a SATA-USB adapter. They may technically exceed the spec on start, although my measurements show it is WELL below the 1.2A max USB current for a Pi 2 or 3, even with two USB dongles.
So I assume they would work with the new 2.5V supplies, and definitely with a 4A supply.
@rastus: you commented on my setup in the DIY section, here:
stack-case-for-raspberry-pi-and-hdd-with-a-hat-dac-or-digi-t3478.html#p13600You can see it is just a Pi 2, the HDD, and a hat DAC. Nothing complicated, no extra effort to get it to work. No magic Western Digital cables, either...
An older drive, or an older Passport, may not work because the startup current is too high.
Since the original post is about the Pi hanging AFTER it started to work, so I assume well AFTER startup, I would guess it may not be just the supply. Since you have a similar setup, have you noticed this yourself? I have not, if it fails due to supply limitations, it fails on start.
edit:
I think it is hanging because of something that happens during the process of updating the library. I would throw a few music tracks on the drive, reboot and play them, repeat a few times, see if it works with a small library. I think you may not be able to play music while updating due to USB limitations. Looks like that is what Frank was getting at (maybe).
P.
