MonoGame: fix block text problem

Yesterday I’ve started to write the UI of my game with monogame on linux. After writing a window system, I’ve tried to display some text with SpriteFonts, but has displayed black blocks instead of text.

Searching on google, someone said that I should create my spritefonts using the monogame content processor; done, but same result.
Searching deeply on google, someone else said to install libtxc_dxtn to fix the problem: this has worked, thanks ShaneG.