Mortal Kombat 1 Errors
Mortal Kombat 1's main problems are online: a generic 'server error' / 'connection lost' when joining matches, plus install failures. These are network errors — poor connection, firewall blocking, IPv6 issues, or corrupt files — not always an outage. Here's what each common problem means and the fastest fix.
Error codes
Server error / connection lost (online)
You can't join or stay in online matches
Cause: A WB/NetherRealm outage, or on your side: poor connection, outdated network drivers, firewall blocking, or IPv6 routing.
- Check WB Games Support and @MortalKombat for maintenance/outage first, and Downdetector for real-time reports.
- Allow Mortal Kombat 1 through Windows Defender Firewall on both Private and Public networks.
- Switch your connection from IPv6 to IPv4 (or enable IPv4 on your router if you only have IPv6).
Online not working / can't matchmake
Servers are up but you still can't play online
Cause: Corrupt game files or a network glitch on your side.
- Fully close MK1 (not just minimize), restart the PC, and relaunch.
- Verify Integrity of Game Files in Steam (Properties -> Local Files).
- Update your network driver and restart your router.
Mortal Kombat 1 won't install
The install or update fails to complete
Cause: Insufficient disk space, corrupted download cache, or client issues.
- Free up disk space and clear the Steam download cache (Settings -> Downloads -> Clear Download Cache).
- Run the launcher as administrator and move the library to a drive with more room.
- Verify the game files after the install completes.
Fixes that work for most Mortal Kombat 1 (PC, PlayStation 5, Xbox Series X|S, Nintendo Switch) errors
- Verify/repair the game files (Steam: Properties -> Installed Files -> Verify integrity; EA app/Epic/Ubisoft: Manage -> Repair) — this replaces corrupted files behind most crashes and fatal errors.
- Update your GPU driver with a clean install (use DDU), and install the latest Microsoft Visual C++ Redistributables (x86 and x64) plus the DirectX End-User Runtime — missing runtimes and stale drivers cause most launch crashes.
- Clear the DirectX Shader Cache (Windows Settings -> System -> Storage -> Temporary files, or Disk Cleanup) and delete the game's local shader/cache folder in AppData\Local, then relaunch.
- Disable overlays (Steam, Discord, GeForce Experience, EA, Epic) and any third-party antivirus/VPN, and add the game to your firewall and antivirus exceptions.
- Check the game's official server/status channels before assuming a local problem — many named connection errors are a maintenance window or outage and clear on their own.
FAQ
How do I fix the Mortal Kombat 1 server error / connection lost?
First check WB Games Support, @MortalKombat and Downdetector to rule out a real outage. If servers are up, allow Mortal Kombat 1 through Windows Defender Firewall on both Private and Public networks, switch your connection from IPv6 to IPv4 (or enable IPv4 on your router if you're IPv6-only), fully close and relaunch the game after a PC restart, and verify the integrity of the game files.
Why won't Mortal Kombat 1 install on PC?
Install failures usually come from low disk space, a corrupted download cache, or launcher issues. Free up disk space, clear the Steam download cache in Settings -> Downloads, run the launcher as administrator, and consider moving the library to a drive with more room. Verify the game files once the install finishes.
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