On lecture no. 60 I am getting below error when running "npm run dev" as you can see in screenshot

[aimanzaheb]

ERROR in ./src/sass/main.scss (./src/sass/main.scss.webpack[javascript/auto]!=!./node_modules/css-loader/dist/cjs.js!./node_modules/sass-loader/dist/cjs.js!./src/sass/main.scss) Module build failed (from ./node_modules/sass-loader/dist/cjs.js): SassError: Invalid CSS after " @if math": expected expression (e.g. 1px, bold), was ".is-unitless($px) {" on line 55 of node_modules/sass-mq/_mq.scss from line 4 of src/sass/_essentials.scss from line 2 of src/sass/main.scss

@if math.is-unitless($px) {

----------^

@ ./src/sass/main.scss @ ./src/js/main.js 3:0-27

ERROR in ./src/sass/single.scss (./src/sass/single.scss.webpack[javascript/auto]!=!./node_modules/css-loader/dist/cjs.js!./node_modules/sass-loader/dist/cjs.js!./src/sass/single.scss)
Module build failed (from ./node_modules/sass-loader/dist/cjs.js): SassError: Invalid CSS after " @if math": expected expression (e.g. 1px, bold), was ".is-unitless($px) {" on line 55 of node_modules/sass-mq/_mq.scss from line 4 of src/sass/_essentials.scss from line 1 of src/sass/single.scss

@if math.is-unitless($px) {

----------^

[aimanzaheb]

Solved - first uninstall latest version of sass-mq npm uninstall sass-mq

then install version 5.0.1 npm install sass-mq@^5.0.1 --save-dev

[imranhsayed]

Thanks @aimanzaheb