I had the same problem, but only with node-sass version 3.4.2. Version 3.4.1 worked fine for me.
This seems to be a known issue in node-sass - https://github.com/sass/node-sass/issues/1222 , however it is not clear which versions are affected.
I fixed it by removing grunt-sass , and then installing the exact version of node-sass that worked correctly (v3.4.1), and then finally reinstalling grunt-sass .
$ npm uninstall grunt-sass $ npm install node-sass@3.4.1 --save-dev $ npm install grunt-sass
This means that grunt-sass uses your installed version, rather than installing its own version, which it defines as "node-sass": "^3.4.0"
Strange, although I indicated the exact version in the installation command, I still ended up with this in my package. json:
"node-sass": "^3.4.1"
So, I manually changed this to the exact version so that other developers on the team get the correct version:
"node-sass": "3.4.1"
Of course, if you find that the only version that works for you is v3.3.0, then use this version in the instructions above.
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