[Solved] Mac Studio M1 Ultra encountering Compressor Batch Transcode Queue Stuck on ‘Waiting’ after update (macOS Sequoia 15.1)

[Aria Moreno]

Diagnostic Hardware Specs: Mac Studio M1 Ultra | OS Version: macOS Sequoia 15.1 | Archive Source: Apple Support Community #256698350

I am running into a persistent issue on my Mac Studio M1 Ultra running macOS Sequoia 15.1.
Whenever the machine encounters Stale background Qmaster / Apple Qconsumer cluster lockfile, the following diagnostic log appears in Console:

Compressor: [qmaster] Service cluster lockfile present: refusing new batch job submission

I verified that hardware connections are intact and tested across different power sources. What is the verified diagnostic procedure to permanently eliminate this symptom?

iMac 24″ M3 (16GB) | AST 2 Diagnostic Station | ESD Workstation | Zurich, CH

Apple Certified Service Technician (ACiT / ACSP) | "Verified Apple Discussions Archive"

[Leo Koenig]

Apple Recommended / Verified Community Solution

This canonical solution was verified and marked as solved in the Apple Support Community archive.

Terminating orphaned qmaster processes and clearing compressor spool storage.

Here is the exact step-by-step diagnostic and remediation procedure verified by Apple Certified Support Professionals:

1. Force quit compressor daemons:

   killall Compressor && killall qmasterd

2. Delete stale batch spool files:

   rm -rf ~/Library/Application Support/Compressor/Storage/*

3. Relaunch Apple Compressor and submit batch job.

Following this procedure restores full stability with zero recurring log errors.

Mac mini M2 (24GB) | Apple Technician Guide Hub | Fluke 87V DMM | Boulder, CO

Apple Certified Support Professional (ACSP) | Apple Certified Service Technician (ACiT / ACSP)

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