npm run dev报错

module.js:549

    throw err;

    ^

Error: Cannot find module 'co'

    at Function.Module._resolveFilename (module.js:547:15)

    at Function.Module._load (module.js:474:25)

    at Module.require (module.js:596:17)

    at require (internal/module.js:11:18)

    at Object.<anonymous> (D:\xampp\htdocs\mukeVue\node_modules\_ajv@5.5.2@ajv\lib\compile\index.js:14:10)

    at Module._compile (module.js:652:30)

    at Object.Module._extensions..js (module.js:663:10)

    at Module.load (module.js:565:32)

    at tryModuleLoad (module.js:505:12)

    at Function.Module._load (module.js:497:3)

老师，我这边报少一个 co 模块，一脸懵逼，百度也geogle不到