Mixins may not be defined within control directives or other mixins

Question

I try to install npm packages. All packages install properly. But when I try to run application using npm start at that time below error occurs:

ERROR in ./node_modules/css-loader?{"sourceMap":false,"importLoaders":1}!./node_modules/postcss-loader?{"ident":"postcss"}!./node_modules/sass-loader/lib/loader.js?{"sourceMap":false,"precision":8,"includePaths":[]}!./src/styles.scss Module build failed:
undefined
^
Mixins may not be defined within control directives or other mixins.
in D:\DailyJS\CIDE_SCHOOL_DEV\node_modules\@angular\material_theming.scss (line 2440, column 10)
Error:
undefined
^
Mixins may not be defined within control directives or other mixins.
in D:\DailyJS\CIDE_SCHOOL_DEV\node_modules\@angular\material_theming.scss (line 2440, column 10)
at options.error (D:\DailyJS\CIDE_SCHOOL_DEV\node_modules\node-sass\lib\index.js:291:26) @ ./src/styles.scss 4:14-187
@ multi ./node_modules/font-awesome/scss/font-awesome.scss ./src/styles.scss
webpack: Failed to compile.

I don't know why this happens? Previously I cloned the repository from Github, and then installed npm packages by using npm install. Then it worked.

But today, it gives this error:

Mixins may not be defined within control directives or other mixins.

Answer 1

Now, i found the solution there was an issue with node-sass pacakge. so install the

npm i node-sass@4.8.1

package then it works.