MU Online opens to a black screen

First checks

• Wait 20 to 30 seconds: some clients load everything before drawing the first screen.
• Press Alt+Enter to switch between window and full screen. If the picture shows up, the screen mode is the problem.
• Check whether it is just you: ask on the server's Discord if other players see the same thing.

Step by step

1. Open your server launcher's options and pick window mode and a resolution your monitor supports (for example 1280×720 or 1920×1080).
2. Update your graphics driver from the vendor's site (NVIDIA, AMD or Intel). Windows Update does not always ship the latest one.
3. Install Microsoft's DirectX End-User Runtime. Windows 10 and 11 include DirectX 12, but old clients use DirectX 9 files that are not installed by default.
4. Right-click the game executable, Properties → Compatibility, tick Disable full-screen optimizations and test. If it persists, try Windows 7 compatibility mode.
5. On laptops with two GPUs, set the game to use the dedicated GPU in the NVIDIA/AMD panel or in Settings → System → Display → Graphics.
6. Turn off overlays from apps such as Discord, screen recorders and FPS counters, then test again.

If nothing worked

Reinstall the client from the server's official link, in a folder outside Program Files (for example C:\Games\MU) to avoid permission issues. Keep a screenshot of any error and send it to the server's support: the cause may be specific to that client.

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