Freezing issue: MacBookPro + USB gear.. thoughts?

[mholloway]

Any folks here using Mac Book Pro and USB gear for live shows? Or just with a USB hub at home? If so, maybe you can help me with this problem (it's not really Ableton specific, but I'm hoping some folks here will run with a similar setup) --

Having issues with MBP freezes in very specific USB-related situations, which are negatively affecting the security of our Live Show rig.

My live setup is:

2015 MacBook Pro w/ Yosemite
MOTU Ultralite II (connects via one of the two MBP usb ports)
Ableton Live 9 Suite (current version)
Powered USB hub (connected to second of two MBZP usb ports)

into the hub run two MIDI controllers -- a small Nektar one octave keyboard, and a larger (but simple) M-Audio keystation.

The issue:

Turning off the midi controllers or unplugging the USB hub (or one of the controllers usb cables) sometimes results in the MBP freezing. It's not a hard crash, it seems to lock the keyboard and mouse functions only, but you can only regain control and reboot through an external source (like a phone or external keyboard that are connected to the MBP).

We've tried two different brands of powered USB hubs and had the same results. However, the freezes are unpredictable and hard to replicate. Sometimes it happens when powering on/off or unplugging, sometimes it doesn't.

While of course we don't plan to unplug or turn off the controllers during the live show, this is obviously a non-ideal situation; cables can get bumped, somebody could unplug something on stage before we go up for our set, etc.

Just posting to see if anybody has this same issue and has any advice / solutions!

thanks,
-Michael

[mholloway]

To anybody who might care / have the same issue, updating the MBP to El Capitan has (so far) resolved this issue.

-M