Cannot read property 'toLowerCase' of undefined npm ERR! code ELIFECYCLE

Question

Cannot read property 'toLowerCase' of undefined

this issue generally comes by below command of react. react-scripts build && rm build/static/**/*.map and issue is like

Cannot read property 'toLowerCase' of undefined npm ERR! code ELIFECYCLE npm ERR! errno 1 npm ERR! react-scripts build && rm build/static/**/*.map

Answer 1

if any body facing this issue please check any reference giving undefined and we are calling the java script tolowercase method by this reference.but it wasn't my issue. the issue was with CSS file. Please validate your CSS once by http://beautifytools.com/css-validator.php and check any attribute is blank or not that might give you above exception. Example: .padding-left-min{padding-left:;}