I've got QGIS 2.8.1 - Wien on my system and often use the Grass tool r.out.xyz. Two of my colleagues have recently installed QGIS 2.18.12, which shows both Grass and Grass7 processing tools. Grass7 doesn't seem to have r.out.xyz (although I thing it should acoording to the reference manual). The Grass processing tools don't work altogether, even when changing the Grass and Msys folder locations in the processing options. I've installed 2.18.12 myself (next to the 2.8.1 version), and indeed there is no Grass7 r.out.xyz tool and the Grass version does't work. In 2.8.1 the Grass r.out.xyz fortunately still works. Are we doing something wrong?