Fixing Halo: Combat Evolved Online After Modding

Modding Halo CE (Custom Edition) often breaks matchmaking due to map/checksum mismatches.

Common Causes

• Modified Maps: Even UI-only mods change the map hash; servers reject non-vanilla clients.
• Conflicting .map Files: Multiple versions in maps/ folder.
• Client/Server Version Mismatch: 1.09 vs 1.10 (no-CD crack) vs. Halo Anti-Cheat (HAC2) builds.
• Corrupted Cache: Old cache/ files conflict with updated maps.

Fixes (In Order)

1. Clean Reinstall: Delete Halo Custom Edition folder. Reinstall from original disc/ISO + 1.10 patch + HAC2.
2. Verify Maps: Keep only stock maps in maps/. Move customs to maps/backup/.
3. Use HAC2 Launcher: HaloAntiCheat.com — handles version sync, auto-updates, and server browser.
4. Join HAC2 Servers: Filter for "HAC2" in server browser; non-HAC2 servers are mostly dead.
5. Port Forwarding: UDP 2302–2303 (game) + 2304 (query) if hosting.

If Using Project Cartographer (PC)

It's a separate, modernized client. Don't mix with legacy CE installs. Use its own server browser.

Backup your checkpoint/ (campaign saves) and profiles/ before wiping.