If you have some issue with the Launcher please check this solution. (WINDOWS LOW VERSIONS)
Step to fixed the issue:
1. Update your window with these tools:
- Microsoft Visual C++ 2015 Redistributable Package (x64): GOOGLE
- Microsoft .NET Framework 4.6.1: GOOGLE
1. Download the Launcher click next link: DOWNLOAD FIXED LAUNCHER
2. Copy and pasthe Launcher in Directory MU LEGEND RELOAD S16 FULL
3. Remplace and execute and play.
Launcher Issues Example: