audiounit - iOS - AudioUnitInitialize returns error code 561017449 -

audiounit - iOS - AudioUnitInitialize returns error code 561017449 -

i have app in app store uses audiounit recording audio.

about 1 time week or seeing users in wild phone call audiounitinitialize fails error code 561017449 0x21707269 or "irp!".

what error code mean? i've been unable find documented. also:

~$ macerror 561017449 unknown error (561017449) @ /usr/bin/macerror5.16 line 40, <data> line 1.

there have been few instances of issue, far there appears no pattern of commonality far device , os version goes.

i'm not including code don't think helpful yet. code working on variety of devices already. @ time i'm interested in learning details specific error.

thanks!

this defined in avaudiosession.h:

avaudiosessionerrorinsufficientpriority = '!pri', /* 0x21707269, 561017449 */

and described "the app not allowed set sound category because app (phone, etc.) controlling it."

ios audiounit