Download and install
The launcher installs the client, keeps everything updated by itself and opens the game. No manual patching.
Updated on August 10, 2026You download a single file, `Launcher.exe`. It handles the rest: it downloads the whole client on the first run, compares what you have against what the server published every time it opens, and replaces only what changed. The game itself (`Main.exe` and the `Data` folder) is not handed out loose, it arrives through the launcher.
- 1file to download
- ~3 GBof installed client
- ~33 thousandfiles in the client
- 0manual patches
How the launcher works
There is no login screen in the launcher. It is anonymous on purpose: the account login happens inside the game, the way it always did in MU. The launcher exists to deliver and update files, not to authenticate you.
- 1It opens
First it checks whether a newer version of itself exists. If so, it downloads it, swaps itself out and reopens.
- 2It compares
It pulls the server file list and compares it against your folder. Every file has a hash, so a corrupted file is detected and downloaded again.
- 3It downloads what is missing
Only what is missing or changed. The download goes into a temporary file and only replaces the real one once it finishes completely.
- 4PLAY
It checks one last time for a new build, asks the server for authorization and opens Main.exe.
Where the game is installed
In the same folder where `Launcher.exe` sits. There is no installer, it does not write to Program Files and it does not touch the Windows registry. Put the launcher in a folder of its own before the first run, because that is where the roughly 3 GB of client will land.
| File or folder | What it is |
|---|---|
| Launcher.exe | The launcher. The only file you download by hand. |
| Main.exe | The game. It arrives through the sync, never as a separate download. |
| Data\ | Maps, models, textures, icons and the language files. |
| config.ini | Your resolution preferences and the server address. The sync downloads it if it is missing and never overwrites yours. |
| launcher.json | Optional. It only exists when the launcher has to be pointed at a different server address. |
Machine requirements
Our client is a 32 bit executable rendering with OpenGL. That defines almost everything that matters.
| Item | What you need |
|---|---|
| System | Windows. There is no Linux or macOS version, and no mobile client. |
| Disk space | Around 3 GB for the client, plus headroom for the new builds that land on top. |
| Memory | The game is 32 bit and works inside a 4 GB addressing ceiling, no matter how much RAM the machine has. More RAM helps the system, not the game. |
| Graphics | A card with OpenGL. The image effects (bloom, per map fog, antialiasing) need shader support and can be switched off on the spot with F9. |
| .NET installed | Not needed. The launcher ships with the runtime bundled in. |
When it gets stuck
| Symptom | Likely cause | What to do |
|---|---|---|
| The launcher looks frozen on startup | A new build came out and it is rechecking the files. | Wait. The status text shows the count while it works. |
| Update failed | The connection dropped midway, or the content server is down. | Close it and open it again. The download resumes and a half finished file corrupts nothing, because it only replaces the real file once it completes. |
| Main.exe was not found | The sync has not finished yet, or the folder was moved after installation. | Let the launcher finish the update before you click PLAY. |
| The game opens and closes by itself | Outdated client, or a file mangled by antivirus. | Open the launcher again: it checks the hashes and replaces any altered file. If it keeps happening, delete the suspect file and let the launcher download it again. |
| Connection error when logging in | Server under maintenance, or a `config.ini` with an old address. | Open the launcher settings screen and save again: it rewrites the correct address into `config.ini`. |