I am in the same boat as you. I updated to El Capitan and my Mbox USB interface is no longer recognized.
Unfortunately, Avid stopped manufacturing the Mbox 2 series in 2010 and ended support for most of the series in September of 2015. While Avid is no longer releasing drivers that will allow the Mbox 2 series of devices to work with Pro Tools 12.0 and above, drivers that are compatible with Pro Tools 9. Question, q, avid / digidesign mbox 2 drivers do not work in el capitan 10.11.0 the avid mbox 2 driver does not work in el capitan and the device is not recognized by the mac / garage band. 2 pro tools 9 drivers on your interests. I use mbox 3rd gen, mini and pro also for the windows win7 xsio win8 default device and never asio mbox 2 the problem. Avid Mbox Pro High-Resolution 8x8 Audio Interface for Mac and PC Brand: Avid. 4.5 out of 5 stars 11 ratings 21 answered questions Currently unavailable. We don't know when or if this item will be back in stock. Get best-in-class sound quality and performance with professional-grade circuitry and premium audio conversion.
If you scan the forums you will find that other MIDI interfaces appear to have stopped working as well, it is not just the Avid MBOX 2. This points to the issue being on Apple's side, but I can't say for sure..
I am hoping for a fix from Apple in the next point release as I am mid-project as well...
In the meantime I would recommend submitting a bug report to Apple. Hopefully the more of these they get the more likely we will see a fix..
Oct 13, 2015 7:04 AM
Following on from our announcement about updated drivers for the Eleven Rack for Pro Tools, Avid have now updated their drivers for their Mbox 3, Mbox Mini (3rd Generation) and Mbox Pro (3rd Generation) interfaces and have included Windows 10 and Pro Tools 12 support.
Avid Mbox 3 Drivers 1.2.9 Notes For Mac OS
- Fixed: AAE error -6101 while record and playback on low buffer sizes
- Supports Mac OS X 10.8.5, 10.9.5, 10.10-10.10.5, 10.11.1-10.11.3
- Tested with Avid-qualified Apple computers
- Check the Pro Tools Operating System Compatibility Chart to see qualified OS versions for Pro Tools
- Core 2 Duo Mac users read this
Avid Mbox 3 Drivers 1.1.0 Notes For Windows OS
Note that Avid have not changed the release date but have amended the notes to include Windows 10 and Pro Tools 12 support.
- Fixed: The 'Updates' button in MBox control panel referred to outdated page
- Supports Windows 7, 8, 8.1 & Windows 10
- Supports Pro Tools 11.0.x - 12.5
Avid Mbox Pro (3rd Generation) Drivers 1.3.2 Notes For Mac OS
Note that Avid have not changed the release date but have amended the notes to include El Capitan and Pro Tools 12 support.
- Supports Mac OS X 10.8.5, 10.9.5, 10.10.5 & 10.11-10.11.3
- Supports Pro Tools 10, 11, 12
- Updates Mbox Pro Firmware to v1.0.4
- Tested with Avid-qualified Apple computers
- Core 2 Duo Mac users read this
Avid Mbox Pro (3rd Generation) Drivers 1.1.0 Notes For Windows OS
Note that Avid have not changed the release date but have amended the notes to include Windows 10 support. Note there is no mention of Pro Tools 12 support in the notes.
- Fixed: Tuner & DSP Effects stop working after updating firmware (note that if Tuner & DSP Effects are not restored, the unit may require a repair)
- Updates Mbox Pro Firmware to v1.0.4
- Windows 7, 8, 8.1 & Windows 10
Mbox 2 Mini Drivers Mac
Avid Mbox Mini (3rd Generation) Drivers 1.3.1 Notes For Mac OS
Note that Avid have not changed the release date but have amended the notes to include El Capitan but check the compatibility notes before updating.
- Supports Mac OS X 10.8.5, 10.9.5, 10.10.5, 10.11.1-10.11.3
- Check the Pro Tools Operating System Compatibility Chart to see qualified OS versions for Pro Tools
- Tested with Avid-qualified Apple computers
- Core 2 Duo Mac users read this
Avid Mbox Mini Driver For Mac
Avid Mbox Mini (3rd Generation) Drivers 1.1.8 Notes For Windows OS
Note that Avid have not changed the release date but have amended the notes to include Windows 10 and Pro Tools 12 support.
Avid Mbox Pro Driver Mac
- Fixed: Crash with Windows Driver Verifier enabled
- Windows 7, 8, 8.1 & Windows 10
- Supports Pro Tools 10.3 – Pro Tools 12.5