I've installed QGIS Las Palmas and still trying to learn its capabilities.

There is however problem with GRASS algorithms grouped in the geoprocessing tools. Some of them work (item 2) and others don't (item 1).

enter image description here

When trying to run any of the group nr 1, following message pops up: enter image description here

How do I configure mentioned folder to make them run?

I am new to QGIS.

QGIS ver: 2.18.5 Las Palmas OS: Win 7 PRO x64

  • Standalone or via OSGeo4W installation? From QGIS 2.16 version, only GRASS 7 tools will be available, even if you still see both the GRASS 6 and GRASS 7 commands from the Processing Toolbox. I'm not sure, but you may try to deactivate GRASS7 commands to get the GRASS6 working again.
    – mgri
    Sep 14, 2017 at 10:55
  • Thanks a lot for the suggestion! So simply those 161 algorithms will not work in the 2.18.5 QGIS version. Should I then try to perform such actions in standalone GRASS and then import to QGIS for further analysis? Originally I've installed QGIS only with its all functions, but when figured out that it does not work I tried to install standalone GRASS. Not yet started however to use it due to other duties.
    – proteus
    Sep 14, 2017 at 11:18

1 Answer 1


The 161 algs work with GRASS 6, the others with GRASS 7. You can run both, if you have installed GRASS 6 and 7, and specified their folders in the options menu.

By default, QGIS comes with GRASS 7, so you can deactivate the GRASS 6 tools in the options unless you have installed GRASS 6 standalone somewhere on your disk.

  • Unfortunately I do not have GRASS 6 but I will look for it. When I have both, is there an option to switch between ver 6 and 7 through Processing Toolbox? Or maybe ver 6 can be accessed in the standalone application only?
    – proteus
    Sep 15, 2017 at 7:15
  • OSGEO4W still has a running GRASS 6 for Windows, so you can have GRASS 6+7 with that (or only take 6). In the toolbox, select either GRASS (6) or GRASS 7 algos. If you specify the path to the standalone GRASS 6 binaries in the Processing options, the GRASS (6) algos will work.
    – AndreJ
    Sep 15, 2017 at 8:24

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