I have QGIS 2.18 and the option to create a New Mapset is unavailable to me. GRASS is installed but when I go to the Plug-Ins>GRASS only Open GRASS Tools and GRASS Options are available to me. These are also the only icons in the GRASS toolbar.
How can I work with GRASS?
I fixed this by changing my Custom path to: /Applications/QGIS.app/Contents/MacOS/grass7
This can be closed.