INCIDENT REPORT: User-Specific Safari Extension Registration Failure - Mac OS Tahoe on new Minimac Pro
INCIDENT REPORT: User-Specific Safari Extension Registration Failure
This report builds on my earlier report presented in
MyndSurfers. (2026, August 24). Safari extensions fail to install on just ONE user account on my MiniMac Pro M4 Tahoe since purchase. Apple Community. Safari extensions fail to install on just… - Apple Community
At my last interaction with Apple Support, I was asked to eliminate Little Snitch from my Minimac. The report below summarizes what has happened.
In short, I successfully eliminated Little Snitch and Micro Snitch. On my main user account, I still cannot add new extensions, or recover extensions that live on my other Minimac accounts. When I install a Safari extension on my new account, (eg Wayback Machine) it fails to register in Safari. BUT it is available and presented for registration on the SAME computer in my troubleshooting admin account. Screenshots to follow.
Dr Google reports as follows.....
User Forum Pseudonym: MyndSurfers
OS / Hardware: macOS Tahoe 26.6.2, Mac mini Pro 4
Core Issue: Safari app-bundled extensions (e.g., Zotero, Wayback Machine) and App Store extensions download successfully to /Applications, but fail to register or populate inside Safari Settings > Extensions on the primary Admin account.
1. Isolation & Diagnostics Established
Cross-User Test: Extensions successfully install, populate, and execute normally on a secondary troubleshooting Admin user account on the same machine.
Scope of Fault: The issue is strictly isolated to the primary user profile directory and does not stem from corrupted core macOS binaries or global Safari frameworks.
2. Remedial Actions Taken (Per Apple Request)
Apple Support previously hypothesized third-party kernel/network extensions were triggering macOS "click-jacking" security layers, silently dropping the extension registrations. The following have been entirely stripped out: [1]
Hardware Isolation: Luna Display dongles and Thunderbolt infrastructure completely disconnected.
Software Removal: Fully deactivated and uninstalled Little Snitch and Micro Snitch.
Process Verification: Confirmed via Activity Monitor that all background network extensions, endpoints, daemons, and low-level system user (_www) intercept filtering processes have been permanently terminated.
Conflict Suppression: Suppressed screen/mouse capture utilities (Screenflow) from running. [I'm not sure about if I did this to Screenflow.
3. User-Level Reset Sequences Attempted (Without Success)
Safe Mode Interventions: Booted into Safe Mode to run purges to isolate background elements.
Directory Purges (via Terminal with Full Disk Access): Hard deleted ~/Library/Caches/com.apple.Safari/and sandboxed app containers at ~/Library/Containers/com.apple.Safari/Data/Library/Caches/.
LaunchServices Rebuild: Executed lsregister -delete paths across system, local, and user domains to break path tracking deadlocks.
App Container Desync: Performed application package compression, deletion, and fresh extractions to trigger new Gatekeeper code signature evaluations. [2] (Using app Zotero downloaded from Zotero.org
4. Current Status & Technical Block
Despite a completely sterile environment with no third-party filter blockages remaining:
Newly installed host applications (installed on faulty user) appear natively in /Applications. The Safari extensions appear for registration in the secondary Troubleshooting account eg Wayback Machine.
Clicking "Activate Now" inside host applications prompts Safari to open, but the extension panel remains entirely blank (new Wayback Machine application, from Mac App Store Safari Extensions
Conclusion
The system is suffering from a localized PlugInKit Database Desync. The user-level pluginkit framework is refusing to discover, index, or append newly added .appex application extensions to Safari’s active layout configuration.
Mac mini, macOS 26.6