Crash when trying to Unmix Transcript

To reproduce:

  1. Select some dialogue on a layer with Time Range Selection
  2. Select “Unmix Transcription”
  3. Select “Language: Auto” or “Language: English” and either quality setting.
  4. Click Apply.

Crash occurs after a few seconds while progress bar is up.

SL 13.0.20 build 454 (arm64)

Apple M3 Pro, macOS 26.6.2 (25G83)

Crash log follows, can also send a project.

SpectraLayers-2026-09-10-192920.ips (98.2 KB)