Product: macOS
Version: macOS 26.4.1 (25E253)
Area: Audio / AVFoundation / AudioToolbox
Summary: We are observing a reproducible crash during audio playback initialization in our macOS application on Apple Silicon systems running macOS 26.4.1.
The crash occurs inside Apple audio frameworks while creating an AudioQueue through AVAudioPlayer/NSSound APIs.
Environment:
Application: Avaya Workplace 3.41.0 Hardware: Apple Silicon (Mac14,7) OS: macOS 26.4.1 Application architecture: x86_64 running under Rosetta Frameworks involved: AppKit (NSSound) AVFAudio AudioToolbox caulk
Crash Type: SIGILL (ILL_ILLOPC)
Observed Stack: -[NSSound play] AVAudioPlayer play AudioQueueNewOutput AudioConverterNewWithOptions caulk::alloc::consolidating_free_map::maybe_create_free_node
Details: The crash occurs while attempting to start ringtone/notification playback from the application.
The failure happens during AudioQueue initialization before actual playback begins.
The crashing thread consistently shows:
caulk AudioToolboxCore AudioToolbox AVFAudio AppKit Application audio helper
We also observed similar AudioQueue initialization stacks on multiple threads, which may indicate concurrent audio queue initialization.
Questions:
Is there any known regression in AudioToolbox/AVFAudio/caulk on macOS 26.4.1 affecting x86_64 applications running under Rosetta? Are there known limitations or unsupported scenarios involving AudioQueue creation from Rosetta-translated applications? Are there recommended alternatives or mitigations for NSSound/AVAudioPlayer usage on macOS 26?
Reproduction:
Launch application on Apple Silicon Mac Trigger ringtone/notification playback Application intermittently crashes during AudioQueue initialization
Additional Notes:
Crash is intermittent but reproducible in customer environments. The application currently uses NSSound/AVAudioPlayer for ringtone playback. We are also investigating whether concurrent sound initialization may contribute to the issue.