LockDown Browser "Installation Failed" on Mac - Complete Fix Guide

Q: I get "Installation Failed" on every download. Is something wrong with my Mac?

Possibly - check your macOS version (older Big Sur / Monterey may have lost trust for current Developer ID certificates). Update macOS first; that resolves the bulk of repeated install failures.

Q: Does "Installation Failed" mean LDB is incompatible with my Mac?

No. LDB supports macOS Ventura 13.0+; if you're on an older macOS (Monterey 12 or earlier), the install correctly fails because LDB will not run there. Update macOS to a supported version.

Q: Can I install LDB without admin privileges?

No. LDB writes to /Applications and requires admin auth on macOS Sonoma+. If you don't have admin rights on your Mac (managed laptop), see the install cluster for IT-coordination paths.

Last updated 2026-05-01 · LDBypass Editorial

The textual "Installation Failed" error during LDB install on Mac most commonly means the .dmg arrived corrupted (interrupted download) or the macOS Gatekeeper rejected the signature. Re-download from your LMS link, verify the file size matches, and retry. If repeated downloads fail, you may be hitting a Digital Signature Error - see Fix 3.

What error Installation Failed means

macOS's installer reports "Installation Failed" when the package fails one of: signature verification, payload integrity check, or post-install script. The most common Mac-side trigger is a partial .dmg from a Wi-Fi drop during download.

Mac-specific causes

Interrupted download (Wi-Fi dropped, browser closed mid-transfer).
Outdated macOS rejecting the current Apple Developer ID intermediate certificate.
Corrupted Apple Installer state from a previous failed install.
Antivirus quarantine modifying the .dmg post-download.
Insufficient disk space (rare but possible if <200 MB free).

Fix 1 - Re-download and verify file size

Delete the failed .dmg from Downloads. Re-download from your LMS link. Compare the file size to what your LMS expected (most LMSes show "~85 MB" or similar near the link). A meaningfully smaller file = corrupt download; redownload.

To compare hash if your LMS publishes one:

shasum -a 256 ~/Downloads/LockDownBrowserOEM-Mac-2-1-5-01.dmg

Fix 2 - Update macOS to the current minor version

System Settings → General → Software Update. The Digital Signature Error variant of "Installation Failed" is fixed by updating macOS to a version that trusts the current Apple intermediate certificate. See Respondus's digital signature KB.

Fix 3 - Disable antivirus during install

Pause Malwarebytes, Bitdefender, Sophos, or Norton for 10 minutes. Re-download .dmg. Install. Re-enable AV afterwards. AV products occasionally modify .dmg files during scan, breaking the signature.

Fix 4 - Free disk space and retry

About This Mac → Storage. If you have <1 GB free, free space (empty Trash, remove old downloads) before retrying.

Fix 5 - Open the .dmg with Disk Utility

If repeated downloads fail, open Disk Utility → File → Open Disk Image, select the .dmg. If it fails to verify here, the .dmg itself is corrupted on the server side or in transit. Try a different network and re-download.

If none of these work

The remaining cases trace to your specific course's Respondus Dashboard configuration - your university IT or instructor needs to look at the server side. Contact them with: the exact error code, the LDB version (right-click LDB.app → Get Info), the macOS version (About This Mac), and the time of your launch attempt.

Frequently asked questions

I get "Installation Failed" on every download. Is something wrong with my Mac?

Possibly - check your macOS version (older Big Sur / Monterey may have lost trust for current Developer ID certificates). Update macOS first; that resolves the bulk of repeated install failures.

Does "Installation Failed" mean LDB is incompatible with my Mac?

No. LDB supports macOS Ventura 13.0+; if you're on an older macOS (Monterey 12 or earlier), the install correctly fails because LDB will not run there. Update macOS to a supported version.

Can I install LDB without admin privileges?

No. LDB writes to /Applications and requires admin auth on macOS Sonoma+. If you don't have admin rights on your Mac (managed laptop), see the <a href="/lockdown-browser-mac/install">install cluster</a> for IT-coordination paths.