Ok after long hours i found the solution. Listen what u have to do:
1. Go to the Downloads section and download the MU Infinity INSTALLER without the Music/Sound.
2. Install MU.
3. Open MU.exe and take all updates.
4. Download the latest patch and extract it in a seperate folder.
5. Copy "config.ini" from the patch (only that file) and paste it in the new MU folder. Replace files.
6. Update again and you should be able to play now.
Make sure you start MU from a shortcut! otherwise it doesn't work.