Clean Reinstall of LockDown Browser on Mac (When Corruption Is Suspected)
When clean reinstall is the right move
You've already tried:
- Force-quit + relaunch (the diagnostic ladder from won't-open cluster).
- Reset Camera / Microphone / Screen Recording permissions (reset procedure).
- Cache-clear (
rm -rf ~/Library/Application Support/LockDown Browser/). - Restart your Mac.
If the issue persists, clean reinstall is next.
The complete clean-reinstall procedure
- Complete uninstall via the complete-removal procedure. Use the Terminal version - faster and more thorough.
- Restart your Mac. Critical for releasing kernel-level handles to LDB and resetting macOS's TCC database state.
- After reboot, do not open any other app first. Sign in to your LMS in Safari, navigate to the assessment that requires LDB, click the download link.
- Install fresh. Open the .dmg, run the installer, authenticate with admin password.
- Launch LDB from your LMS link. macOS prompts for Camera, Microphone, Screen Recording - click Allow on each.
- Run the practice exam your instructor enabled to verify the system check completes.
- Quit LDB. Permission state is now clean for the real exam.
What this resolves
| Symptom | Reason clean reinstall helps |
|---|---|
| Persistent freezes during launch | Stuck cached config + corrupted bundle, both cleared |
| "Permission denied" despite System Settings showing allowed | TCC database inconsistency cleared by uninstall + reboot |
| "Configuration Failed" surviving cache-clear | Network registration retried fresh |
| Webcam check spinning indefinitely | AVFoundation state reset |
| Repeated -21/-101/-105 errors | Stale Dashboard cache cleared |
| Codesign verification errors | Fresh signature pulled from LMS link |
What clean reinstall does NOT resolve
- Network blocks (-7, A4): The network is the problem, not LDB.
- Hardware failures (broken webcam/mic): No software fix.
- Server-side Dashboard issues: Your university IT or instructor needs to fix the Dashboard.
- Persistent macOS issues (kernel extension conflicts from third-party AV): need to address those separately.
How long does clean reinstall take?
| Step | Time |
|---|---|
| Complete uninstall | 30 seconds |
| Reboot | ~1 minute (Apple Silicon) / 1-2 minutes (Intel) |
| Re-download .dmg | 30 seconds (depending on bandwidth) |
| Run installer | 30 seconds |
| Approve TCC dialogs | 30 seconds |
| Run practice exam | 5-10 minutes |
Total: ~10-15 minutes including practice exam. Don't do this on exam day; do it the day before.
If clean reinstall doesn't fix it
Save the most recent crash report from ~/Library/Logs/DiagnosticReports/LockDown Browser-*.ips, attach to a Respondus support ticket via support.respondus.com, and CC your university IT. Provide:
- macOS version (About This Mac).
- LDB version after reinstall.
- Specific symptom that persists.
- What you tried (this clean reinstall + cache-clear + permission resets).
- The .ips file.
Frequently asked questions
Will I lose my exam history if I reinstall LDB?
No - exam history lives in your LMS (Canvas, Blackboard, etc.), not in LDB. Reinstalling LDB doesn't affect grades or attempt records.
How often do I need to reinstall?
Almost never under normal conditions. Reinstall is a recovery procedure, not maintenance. If you find yourself reinstalling repeatedly, the underlying issue is elsewhere (hardware, macOS, network).
Can I reinstall to a newer LDB version specifically?
Yes - your LMS link delivers the current Respondus-shipped build. Each reinstall gets the latest. If you want a specific older version, you'd need it from a Respondus support ticket; this is rare.