Hi, i´m using krita a lot this days so i´m trying everything, yesterday i tried the layer mask but doesn´t work, i switched between white and black but nothing works.

I intend to install kubuntu or linux mint kde on my computer but in the meantime I am working on windows 7 with krita.

Hi Jramirez,
The current way to work of layer mask is based on 'alpha/transparency' , so just use the shortcut 'E' to erase on the mask , or fill it with a brush.