Error: Node Sass does not yet support your current environment: Windows 64-bit with false

E:\A Prem World\Team_Work_Tasks\Anjali\Anjali_20160524\QuizApp_20160524_01_Anj>ionic serve -l
(node:4772) fs: re-evaluating native module sources is not supported. If you are using the graceful-fs module, please update it to a more recent version.
There is an error in your gulpfile:
Error: Node Sass does not yet support your current environment: Windows 64-bit with false
For more information on which environments are supported please see:
TODO URL
    at Object.<anonymous> (E:\A Prem World\Team_Work_Tasks\Anjali\Anjali_20160524\QuizApp_20160524_01_Anj\node_modules\node-sass\lib\index.js:12:11)
    at Module._compile (module.js:541:32)
    at Object.Module._extensions..js (module.js:550:10)
    at Module.load (module.js:456:32)
    at tryModuleLoad (module.js:415:12)
    at Function.Module._load (module.js:407:3)
    at Module.require (module.js:466:17)
    at require (internal/module.js:20:19)
    at Object.<anonymous> (E:\A Prem World\Team_Work_Tasks\Anjali\Anjali_20160524\QuizApp_20160524_01_Anj\node_modules\gulp-sass\index.js:187:21)
    at Module._compile (module.js:541:32)

This error message does not indicate a problem with Ionic, but rather with node-sass, which is specified to execute in your Gulp file.

The node-sass error:

Node Sass does not yet support your current environment

indicates that the version of node-sass you are trying to run is not compatible with the version of node installed.

Check the Node Sass release notes for the version of node-sass you have, to see which version of node is required.

If the version of node is wrong, you must downgrade node, or upgrade node-sass, until you have a compatible pair. If the node version is supported, you may just need to run:

npm rebuild node-sass

(with -g if node-sass was installed globally).

If that doesn't work, you can:

npm uninstall node-sass && npm install node-sass

(again, with -g if necessary).

This github issue has lots of more info on this.