How to fix problem with fonts (squares)

Some players see squares in the game instead of text:

That means they are missing windows font called Arial Unicode MS.
It's a common error for all new Mu Online clients, so make sure to follow the easy steps listed below:

1. Close the game.
2. Open the game client.
3. Open the "Fonts" folder.
4. Right click with your mouse on the file "ARIALUNI" and click Install.
5. Start the game.