module thew error

module.js:340
    throw err;
          ^
Error: Cannot find module '/var/www/html/angular-express-mongoose-seed/app.js'
    at Function.Module._resolveFilename (module.js:338:15)
    at Function.Module._load (module.js:280:25)
    at Function.Module.runMain (module.js:497:10)
    at startup (node.js:119:16)
    at node.js:935:3
