**System Information**
Operating system: macOS-11.4-x86_64-i386-64bit 64 Bits
Graphics card: AMD Radeon Pro 575 OpenGL Engine ATI Technologies Inc. 4.1 ATI-4.5.14
**Blender Version**
Broken: version: 3.0.0 Alpha, branch: cycles-x, commit date: 2021-07-09 16:01, hash: `rB9aa5aeee46ae`
Worked: ( version: 3.0.0 Alpha, branch: cycles-x, commit date: 2021-07-05 15:23, hash: `048a515ef428`)
(happens in master, too)
This apparently regressed in {rB0153e99780aef64913dfd4c323984874bf688249}
**Short description of error**
[Open up scene and hit render button results in quitting immediately. Mist, AO layers + denoising in compositing used. Works in previous version (see above) except of cause for the AO layer]
**Exact steps for others to reproduce the error**
[Open the blend file and hit the render button, and it will quit. Not so in previous blender version/s. Mac Crashlog attached.]
[Based on the default startup or an attached .blend file (as simple as possible)]
{F10219711}
{F10219712}
Thanks in advance
SG