CASE ID: #7586
LOG DATE: JAN 2026

Case Study: Logic Pro Freezing During Audio Unit Scan (Halo 2 / DH Plugins)

Panic Index CRITICAL STOPPAGE
Technical Depth CORRUPTION
RESOLVED

Target Environment

macOS Sequoia + Logic Pro

Reported Symptom

“Logic Pro hangs indefinitely on startup during 'Scanning Audio Units' phase.”

Consultant’s Assessment

Root Cause / Concept Plugin expansion metadata installed without its sample content, corrupting the parent VST/AU.
Outcome Faulty expansion pack uninstalled. Core plugin functionality and DAW stability restored.
Intervention Risk
MODERATE

System Specifications:

  • OS: macOS Sequoia 15.6
  • DAW: Logic Pro 11.1.2
  • Primary Plugin Issue: Halo 2 by DH Plugins
  • Secondary Plugin Issue: UJAM Virtual Instruments

Symptoms

The client reported that Logic Pro 11 was consistently failing to open, hanging indefinitely during the “Scanning Audio Units” phase. Force quitting was required to exit the application. Previously, the client noted that the Halo 2 plugin appeared “greyed out” and unresponsive within Logic before the total startup failure began.

Diagnosis & Troubleshooting

Initial investigation using Activity Monitor was inconclusive. The troubleshooting process proceeded as follows:

  1. Component Isolation: Removed recently installed plugins from the /Library/Audio/Plug-Ins/Components folder.
    • Observation: Logic would freeze on UJAM plugins during the scan. These were removed, but the freeze persisted when scanning Halo 2.
  2. Full Component Reset: Removed all third-party components. Logic Pro loaded successfully, though some plugin references remained visible despite the folder being empty.
  3. Preferences & Cache Wipe:
    • Deleted com.apple.logic10.plist.
    • Cleared the Audio Unit Cache (com.apple.audiounits.cache) and the Audio Unit Validation Tool cache.
    • Result: Logic loaded with a clean slate.
  4. Reintroduction & Reinstall: Re-added Halo 2. The freeze returned. We completely uninstalled and reinstalled the Halo 2 base plugin.
    • Result: Halo 2 loaded successfully.

The Root Cause

The issue re-emerged when attempting to install the “Beast Mode” expansion pack for Halo 2 via the DMG installer.

  • The expansion pack installs the license/metadata but requires a separate step to download the actual sample content.
  • The content download repeatedly failed with the error: “Download aborted, try again,” despite changing target locations (e.g., /Users/Shared/Halo 2 Content) and checking permissions.
  • Conclusion: Installing the expansion pack metadata without successfully completing the content download corrupted the Halo 2 instance, causing Logic to hang on startup or the plugin to appear greyed out.

Solution & Outcome (Partial)

  • Immediate Fix: The “Beast Mode” expansion pack was uninstalled. This restored the functionality of the base Halo 2 plugin and allowed Logic Pro to open and operate without crashing.
  • Status: Unsolved. While the Logic system is restored and stable, the specific download error for the expansion pack persists.
  • Next Steps: The download failure is likely due to a client-side firewall/antivirus block (specifically Norton Auto-Protect was suspected) or a server-side issue with DH Plugins. This will be addressed in a follow-up session.

Need Help With This Issue?

If you are searching for professional help with Logic Pro crashes, Audio Unit validation loops, or specific issues with DH Plugins on macOS Sequoia, expert assistance is available. We provide specialized one-on-one remote support services for audio support to diagnose and resolve complex DAW and plugin conflicts just like this one.