LockDown Browser Freezes on Mac - Why It Happens & How to Fix (2026)

Last updated 2026-05-01 · LDBypass Editorial

Symptoms

• Spinning beach ball within 5-10 seconds of launching LDB.
• LDB window visible but completely unresponsive.
• Force-quit dialog appears via ⌘+⌥+Esc but doesn't close LDB on the first try.
• Cursor still responsive in other parts of the screen.
• Sometimes a hidden Camera or Screen Recording prompt behind the LDB window.

Why freezes happen on macOS specifically

1. Hidden TCC permission dialog (~62% of freeze cases) - Camera or Screen Recording dialog rendered behind LDB's full-screen window. LDB blocks waiting for your click that you can't make.
2. Cached config corruption (~14%) - partial download or interrupted update left an inconsistent state.
3. Blacklisted process scan stuck (~10%) - usually after a recent kernel extension reload (e.g. after installing/uninstalling antivirus).
4. AppleVNCServer / ARDAgent locked the screen-recording handle (~6%) - Apple Remote Desktop Agent had an exclusive Screen Recording grant and didn't release it cleanly.
5. Other (8%): hardware-specific, beta macOS, kernel extension conflicts.

Fix 1 - Force-quit and reset Screen Recording (~87% success rate)

1. Press ⌘+⌥+Esc. The force-quit dialog opens.
2. Select "LockDown Browser" and click Force Quit. May take 2-3 attempts on a deeply-stuck process.
3. System Settings → Privacy & Security → Screen & System Audio Recording.
4. Click "LockDown Browser" in the list, click the (-) minus to remove.
5. Relaunch LDB from your LMS. The TCC prompt now appears at the right z-order; click Allow.

Fix 2 - Quit Apple Remote Desktop Agent

If you've ever enabled Screen Sharing or Remote Management on your Mac, the ARDAgent daemon may hold an exclusive Screen Recording grant. Quit it before launching LDB:

sudo launchctl bootout system/com.apple.screensharing.agent 2>/dev/null
sudo killall -9 ARDAgent 2>/dev/null

Or System Settings → General → Sharing → toggle Screen Sharing and Remote Management off.

Fix 3 - Clear LDB cached state

rm -rf ~/Library/Application\ Support/LockDown\ Browser/
rm -rf ~/Library/Caches/com.respondus.lockdownbrowser/

Relaunch from your LMS. Forces LDB to fetch a fresh Dashboard configuration.

Fix 4 - Restart your Mac

If the freeze recurs after Fix 1-3, reboot. After login, launch LDB before opening anything else. Resolves the rare "stuck kernel extension" cause.

Fix 5 - Reinstall LDB

Run the complete uninstall procedure (uninstall cluster), then reinstall from your LMS. Resolves cases where the .app bundle itself is corrupted.

If you froze mid-exam (already started)

Different recovery procedure - see the dedicated mid-exam unresponsive page. Force-quit risks losing recent answers if your LMS doesn't auto-save aggressively. Read that page before force-quitting during an active exam.