What is the content of C:\OSGeo4W64\etc\ini and C:\OSGeo4W64\Apps? What is the path to your R installation? Not sure what's going on as tested here on several win 10 boxes, and it works on all of them. ----- best regards Helmut -- Sent from: http://osgeo-org.1560.x6.nabble.com/Grass-Users-f3884509.html