Everything was fine, I would make a change, run grunt less:sitename and the changes would be reflected in the browser. Then all of a sudden I get this...
NameError: variable @modal-popup-breakpoint-screen__m is undefined
The file which this points to is in the Magento_Checkout module which I have not touched.
As this is a magento module and has nothing to do with any of my custom code I dont know where to go from here....
I have faced this issue when we upgrade to Magento 2.1.16:
I have resolved the issue by adding below changes to the theme
1) ~/app/design/frontend/ThemePackage/theme/web/css/source/_theme.less add at line 29: @import 'components/_modals_extend.less';
2) Add "components/_modals_extend.less" folder and file at ~/app/design/frontend/ThemePackage/theme/web/css/source/
3) ~/app/design/frontend/ThemePackage/theme/web/css/source/components/_modals_extend.less add at line number 16**:**
@modal-slide-header__padding-vertical: 2.1rem; // added from \vendor\magento\magento2-base\lib\web\css\source\components_modals.less
@modal-popup__padding: 3rem; // added from \vendor\magento\magento2-base\lib\web\css\source\components_modals.less
@media-common : false; //custom from magento/theme-frontend-blank/web/css/styles-l.less
Here ThemePackage/theme can be any theme package and theme name.
Issues may arise if you are missing .htaccess files from your pub and/or static folders.
Please double-check your pub and pub/static folders to see if they contain the necessary .htaccess files.
