prompt node prompt 'webpack-dev-server' is not an internal or external command, nor is it a runnable program
first execute
npm install -g webpack
npm install -g webpack-dev-server
Not reporting 'webpack-dev-server' is not an internal or external command, nor is it the fault of a runnable program
but then report
Cannot find module 'webpack/bin/config-yargs'
After executing webpack -v prompt to execute run npm install -D webpack-cli select yes
Problem solved after