Today VPN so bad, so be prepared to look at VUE front-end code. Because it is a new party sent me, so I think first run up the code. The results showed that sent me the code no node_modules.
Solutions
npm install express
After a successful compilation, but build error, see the error content suggestive of a scss file could not be loaded. After careful investigation found .env.production configuration file does not specify VUE_APP_Name parameters in the build environment, which happens in vue.config.js This variable is used. Comparison of the parameter values .env.development, copied. After the build is OK