iOS 8 doesn't work with some USB MIDI Class Compliant devices

Originator:szantog
Number:rdar://18511203 Date Originated:01/10/2014
Status:open Resolved:
Product:iOS Product Version:8
Classification:Serious Bug Reproducible:Always
 
The Allen&Heath Xone:K2 is a popular USB Audio and MIDI Class Compliant DJ device. It was working properly before iOS 8. Now only audio works, it doesn't show up as a Core MIDI device.

Steps to Reproduce:
1. Connect the Allen&Heath Xone:K2 using a powered USB hub and the Camera Connection Kit.
2. Launch a MIDI tester app, for example MIDI Wrench.
3. The K2 doesn't show up as a MIDI device.

Expected Results:
The K2 appears as a MIDI device, and MIDI apps (for example MIDI Wrench or DJ Player) receive MIDI events from it.

Actual Results:
The K2 doesn't show up as a MIDI device.

Version:
iOS 8.0.2 (12A405)

Notes:
Here is the iOS log for this bug:

Oct  1 07:53:08 Szanto-Gabors-iPad Midi Tool[495] <Error>: assertion failed: 12A405: libxpc.dylib + 51955 [84E1BEE3-B897-39DD-9A7B-D061B6B252C5]: 0x7d
Oct  1 07:53:08 Szanto-Gabors-iPad Unknown[495] <Error>: 
Oct  1 07:53:09 Szanto-Gabors-iPad BTServer[63] <Error>: Core       Ignoring registration on unsupported hardware for application "com.apple.MIDIServer"
Oct  1 07:53:09 Szanto-Gabors-iPad BTServer[63] <Error>: Core       Ignoring registration on unsupported hardware for application "com.apple.MIDIServer"
Oct  1 07:53:09 Szanto-Gabors-iPad BTServer[63] <Error>: Core       Ignoring registration on unsupported hardware for application "com.apple.MIDIServer"
Oct  1 07:53:09 Szanto-Gabors-iPad BTServer[63] <Error>: XPC        Ignoring XPC message as session is NULL
Oct  1 07:53:09 Szanto-Gabors-iPad BTServer[63] <Error>: XPC        Ignoring XPC message as session is NULL
Oct  1 07:53:09 Szanto-Gabors-iPad kernel[0] <Notice>: USBF:	24505.642	Standard

Configuration:
iPad 2, iPad 4, iPad Air, iPhone 5

Comments

Duplicate

"Engineering has determined that your bug report (18511203) is a duplicate of another issue (18511419) and will be closed."

Let's hope the other developer who submitted this will co-operate fast with Apple.

By szantog at Oct. 5, 2014, 12:09 p.m. (reply...)

Additional results

  • tested with 2 AH:K2 devices, same result
  • tested on iPad 4 with 8.0.2 with same result
  • also tested on iPhone 5S with 8.0.2 with same result
By webdevotion at Oct. 1, 2014, 6:34 a.m. (reply...)

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