LockDown Browser Error -118 on Mac (Configuration / Network Fix)

Last updated 2026-05-01 · LDBypass Editorial

What error -118 means

Error -118 fires at the boundary of the configuration error range - often when LDB and the Dashboard agree on the configuration but a transient network failure during the handshake left the state half-applied. The next launch surfaces -118 because the half-applied state is invalid.

Mac-specific causes

• Stale or partially-written LDB cached config.
• Transient network failure during a previous launch handshake.
• Course re-published while you had LDB open.

Fix 1 - Cache-clear + retry

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

Relaunch from LMS. -118 typically resolves on the next launch.

Fix 2 - Verify network is stable

Test reachability with curl -I https://www.respondus.com. If latency is >500ms or the request times out, switch networks before retrying.

Fix 3 - Reinstall if cache-clear does not help

Run the complete uninstall + fresh install from your LMS link. See uninstall cluster.

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.