Can anyone help me with this:

I'm trying out the 'threads' sample under Visual Studio 1.8.0. Not having much luck. I'm a newbie and have followed the Video tutorials to the letter and tried everything, including a complete new install of 1.8.0, but whenever I try to do anything in the ACTIONS list (build, pristine build, flash etc) I get this error.
If I try running commands from 'west', eg west build, west flash, they all work fine.