安装了vue-loader vue-template-compiler -D 成功之后运行 vue-loader -V和vue-template-compiler -v提示不是内部文件.

但是在package.json 里发现已经安装了版本.

相关代码

// package里的版本： "vue-loader": "^15.7.0",

                   "vue-template-compiler": "^2.6.10",
                   
  尝试重新安装，并成功：

D:socialwebpack>cnpm i vue-loader vue-template-compiler -D
√ Installed 2 packages
√ Linked 7 latest versions
√ Run 0 scripts
√ All packages installed (1 packages installed from npm registry, used 1s(network 1s), speed 86.9kB/s, json 9(98.02kB), tarball 0B)

再次运行npm run dev结果如下：

D:socialwebpack>npm run dev

webpack@1.0.0 dev D:socialwebpack
webpack-dev-server --open --port 3000 --contentBase src --hot

internal/modules/cjs/loader.js:584

throw err;
^

Error: Cannot find module 'ms'

at Function.Module._resolveFilename (internal/modules/cjs/loader.js:582:15)
at Function.Module._load (internal/modules/cjs/loader.js:508:25)
at Module.require (internal/modules/cjs/loader.js:637:17)
at require (internal/modules/cjs/helpers.js:22:18)
at setup (D:\social\webpack\node_modules\_debug@4.1.1@debug\src\common.js:14:25)
at Object.<anonymous> (D:\social\webpack\node_modules\_debug@4.1.1@debug\src\node.js:236:37)
at Module._compile (internal/modules/cjs/loader.js:701:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:712:10)
at Module.load (internal/modules/cjs/loader.js:600:32)
at tryModuleLoad (internal/modules/cjs/loader.js:539:12)

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! webpack@1.0.0 dev: webpack-dev-server --open --port 3000 --contentBase src --hot
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the webpack@1.0.0 dev script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR! C:Users53292AppDataRoamingnpm-cache_logs2019-03-27T15_58_12_176Z-debug.log

请问朋友们怎么解决呢，是不是版本问题呢？