User profile for user: MyndSurfers
MyndSurfers Author
User level: Level 1
46 points

Safari extensions fail to install on just ONE user account on my MiniMac Pro M4 Tahoe since purchase

On my main user account, I cannot view the Safari extensions that I view in other user accounts on this same miniMac

  1. I select a new extension from the App Store
  2. I look for it in Safari Settings. It's not there.
  3. I Open a low-use troubleshooting admin account on the same Mac.
  4. The extension I just acquired IS there, but not activated. So I check ON
  5. I add another extension to this troubleshooting account. It adds OK. Bought through the same App Store account.
  6. I return to the main user account. Neither extension is there.
  7. I restart in Safe mode into the Main account
  8. Neither extension is there.


I initially thought this was an issue with installing the Zotero extension downloaded with the Zotero app from the Zotero.org download pages.

But Zotero support had me confirm that both the Zotero extension, and app.store extensions installed OK on an alternative user on the same computer, my troubleshooting account.


So, I suspect something troublesome with the Safari ecosystem on my main user login on my Minimac.


I'm working with Apple Support Sydney on this.


Mac sytem

Mini Mac 2024

Apple M4 Pro

48 GB

Tahoe 26.6.2


Safari

26.6.2 (21624.5.1.11.3)


I'm a rare user of Safari extensions, but getting the Zotero Safari extension to activate is truly important to me. The Zotero extension installs OK on my MacBook Air 2019 Intel UHD, Sonoma 14.8.7, Safari 26.5.2.


I suspect I have not successfully installed ANY extensions on the problematic Safari account since I purchased the Minimac, about December 2024.


The Chrome Zotero extension works OK on all users on the Minimac.


I recently switched my use of Chrome as my default browser to Safari around April, May this year, 2026. I pulled across all my website passwords etc in this transition. It seemed a good idea.





Mac mini, macOS 26.6

Posted on Aug 23, 2026 5:33 PM

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User profile for user: MyndSurfers
MyndSurfers Author
User level: Level 1
46 points

Posted on Sep 16, 2026 4:59 PM

UPDATE RESOLVED: Localised PlugInKit Database Corruption Fixed via Sterile Account Migration

To everyone following my thread regarding Safari extensions failing to install or check on just ONE user account: We have officially broken the deadlock.


With Apple Support I conducted exhaustive low-level testing. The testing under the instruction of Apple Engineers included


  1. Force-killing orphaned system network extensions (at.obdev.littlesnitch.networking) running under system users like _www, clearing sandboxed caches, and
  2. Attempting manual database overrides via command-line lsregister and pluginkit paths—


Result: the extension checkboxes continued to reject activation clicks. 


We strongly suspect the culprit was a deep PlugInKit Database Desync specific to the primary home directory, carried over from an old 2017 machine migration.


Assumption: macOS Tahoe's strict extension security layers permanently deadlocked trying to parse modern sandboxed extension permissions over the legacy database tables.


The Solution: I successfully executed an extreme precautionary incremental migration to a fresh Admin user profile on the same Mac mini. 


By completely abandoning the old ~/Library folder, the corrupted database was left behind. I cross-loaded my raw assets via the global /Users/Shared/ directory, using the Command-Copy then Command=Paste in Finder to completely rewrite file permissions.


Critical pro-apps with external databases (Zotero and Lightroom Classic) were re-linked directly to my external Samsung SSD data folders.


The moment the clean user profile was active, the Control Isolation Proof succeeded instantly: App Store and app-bundled Safari extensions activate and stay checked perfectly. That is Wayback Machine and Zotero from Zotero.org for example.


Recommendation

If you are experiencing this exact localized bug following a migration across historical OS versions, I suggest do not waste days on terminal hacks; pull your raw data assets out and stand up a fresh user profile.


This problem first manifest itself in May 2026. It's taken me until now, late September 2026 to resume having a fully-functioning Mini Mac. See APPENDIX A for the justification of the cause and resolution.

APPENDIX A: Evidence for the Problem Diagnosis


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User profile for user: MyndSurfers
MyndSurfers Author
User level: Level 1
46 points

Sep 16, 2026 4:59 PM in response to MyndSurfers

UPDATE RESOLVED: Localised PlugInKit Database Corruption Fixed via Sterile Account Migration

To everyone following my thread regarding Safari extensions failing to install or check on just ONE user account: We have officially broken the deadlock.


With Apple Support I conducted exhaustive low-level testing. The testing under the instruction of Apple Engineers included


  1. Force-killing orphaned system network extensions (at.obdev.littlesnitch.networking) running under system users like _www, clearing sandboxed caches, and
  2. Attempting manual database overrides via command-line lsregister and pluginkit paths—


Result: the extension checkboxes continued to reject activation clicks. 


We strongly suspect the culprit was a deep PlugInKit Database Desync specific to the primary home directory, carried over from an old 2017 machine migration.


Assumption: macOS Tahoe's strict extension security layers permanently deadlocked trying to parse modern sandboxed extension permissions over the legacy database tables.


The Solution: I successfully executed an extreme precautionary incremental migration to a fresh Admin user profile on the same Mac mini. 


By completely abandoning the old ~/Library folder, the corrupted database was left behind. I cross-loaded my raw assets via the global /Users/Shared/ directory, using the Command-Copy then Command=Paste in Finder to completely rewrite file permissions.


Critical pro-apps with external databases (Zotero and Lightroom Classic) were re-linked directly to my external Samsung SSD data folders.


The moment the clean user profile was active, the Control Isolation Proof succeeded instantly: App Store and app-bundled Safari extensions activate and stay checked perfectly. That is Wayback Machine and Zotero from Zotero.org for example.


Recommendation

If you are experiencing this exact localized bug following a migration across historical OS versions, I suggest do not waste days on terminal hacks; pull your raw data assets out and stand up a fresh user profile.


This problem first manifest itself in May 2026. It's taken me until now, late September 2026 to resume having a fully-functioning Mini Mac. See APPENDIX A for the justification of the cause and resolution.

APPENDIX A: Evidence for the Problem Diagnosis


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User profile for user: MyndSurfers
MyndSurfers Author
User level: Level 1
46 points

Aug 24, 2026 2:09 AM in response to MyndSurfers

Further update.


On my MacBook Air, the Safari extensions installed on my MiniMac were available for installation directly. I had to download Zotero from its download link, the usual situation.

There was one error message that crashed Safari, which required Safari to restart.


MacBook Air 13 inch 2019

Intel UHD

16 GB

Sonoma 14.8.9


Safari 26.6.1


Screenshots as follows

A. View of Extensions available for download and install on MacBook Air



B. Oops - Safari quit unexpectedly as I requested Extensions to download to MacBook AIr


C. Problem Report for Safari



D. Restart Safari. Extensions available and activated


E. Two of the three extensions Enabled. Zotero missing. Enable Right shown twice. Curious!


F. Zotero installed OK, after download and install of Zotero 10 from https://www.zotero.org/download/



So, all three extensions installed OK on my MacBook Air, installed on my Minimac Pro on two different admin accounts.


Troublesome main user account still not showing any Safari extensions

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Safari extensions fail to install on just ONE user account on my MiniMac Pro M4 Tahoe since purchase

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