Apply button does not work on macOS Tahoe 26.2 — workaround: launch with -v flag

[terzigolu]

Environment:

• BetterDisplay 4.1.2 (build 47018), licensed
• macOS Tahoe 26.2 (Build 25C56)
• MacBook Pro M2 Max (Mac14,5), 64GB RAM
• Built-in display: Color LCD (3024x1964 native, vendor 0x610, product 0xA04E)
• SIP: enabled

Bug Description:
When BetterDisplay is launched normally (Finder, Spotlight, or Login Items), the Apply button for resolution/override changes appears to process but nothing actually changes. Undo works, but Apply has no effect. No error is shown in the UI.

Diagnosis:

• Code signature: valid, notarized, stapled
• Accessibility permission: granted in System Settings
• TCC database: shows zero entries for pro.betterdisplay.BetterDisplay despite permission being visually enabled in System Settings
• Override file at /Library/Displays/Contents/Resources/Overrides/DisplayVendorID-610/DisplayProductID-a04e is written successfully but not applied
• overrideSettingsLastAppliedDisplayTagIdList remains empty "[]"
• overrideSettingsLastChangedBootID remains null "0001-01-01 00:00:00 +0000"
• No BetterDisplay entries in system log (log show)
• Tried: full TCC reset (tccutil reset Accessibility), reboot, re-grant permission, clean reinstall x3, chown override file to root:wheel — none fixed the issue

Workaround:
Launching with -v (verbose) flag makes Apply work correctly:

/Applications/BetterDisplay.app/Contents/MacOS/BetterDisplay -v

Created a LaunchAgent to auto-start with -v flag. This suggests the -v flag changes initialization order or Accessibility API call path, bypassing a Tahoe-specific timing/permission bug.

Steps to Reproduce:

1. Install BetterDisplay 4.1.2 on macOS Tahoe 26.2
2. Grant Accessibility permission
3. Open BetterDisplay normally
4. Change resolution or enable any override
5. Click Apply — nothing happens
6. Kill app, launch from terminal with -v flag
7. Repeat steps 4-5 — Apply works

[waydabber]

Hmm. This might be some kind of permission issue. Launching from Terminal (-v should not matter) probably fixes this. The app might be running in sandbox (rare issue, usually happens when the app was mistakenly launched from the Downloads folder or DMG originally) when normally launched.

[terzigolu]

Thanks for the response. I don't think it's a sandbox issue — the app is properly installed in /Applications (not launched from DMG or Downloads), and all permissions (Accessibility, Automation, System Events) are granted.

I've also done a complete cleanup of all BetterDisplay-related files 3 times with Claude Code — preferences, caches, application support, launch agents, saved states, everything. Fresh install each time.

Launching from Terminal works as a workaround, but the issue persists when launching normally from Finder. Any other ideas what might cause this difference?

[waydabber]

The apple uses Apple Script to elevate permissions, sometimes that has an issue, but it's rare and usually some macOS specific problem which is difficult to manage. I recommend looking at the logs. Since the issue does not happen when you start from terminal using -v, I recommend looking at the console for the log output and see if there is any specific error message.

Here is how you can do that:

https://github.com/waydabber/BetterDisplay/wiki/Enable-console-logging

Let me know if you find anything.

(I'll move this issue over to discussions)