title: ERROR in Error: Metadata version mismatch
body: <p>i'm new to angular ( using v.4 for now) and i'm working on a project for my studies and it's also my first time trying Primeng modules. 
  I  tried to integrate the "datagrid" to my project and after i did "ng serve", i've got this error : </p>
  
  <p>[enter image description here][1]</p>
  
  <p>ERROR in Error: Metadata version mismatch for module C:/Users/ASUS/Desktop/test1/node_modules/primeng/components/common/api.d.ts,
  found version 4, expected 3, resolving symbol AppModule in C:/Users/ASUS/Desktop/test1/src/app/app.module.ts, resolving symbol App
  Module in C:/Users/ASUS/Desktop/test1/src/app/app.module.ts
      at Error (native)
      at syntaxError (C:\Users\ASUS\Desktop\test1\node_modules\@angular\compiler\bundles\compiler.umd.js:1729:34)
      at simplifyInContext (C:\Users\ASUS\Desktop\test1\node_modules\@angular\compiler\bundles\compiler.umd.js:24979:23)
      at StaticReflector.simplify (C:\Users\ASUS\Desktop\test1\node_modules\@angular\compiler\bundles\compiler.umd.js:24991:13)
      at StaticReflector.annotations (C:\Users\ASUS\Desktop\test1\node_modules\@angular\compiler\bundles\compiler.umd.js:24418:41)
      at _getNgModuleMetadata (C:\Users\ASUS\Desktop\test1\node_modules\@angular\compiler-cli\src\ngtools_impl.js:138:31)
      at _extractLazyRoutesFromStaticModule (C:\Users\ASUS\Desktop\test1\node_modules\@angular\compiler-cli\src\ngtools_impl.js:109:
  26)
      at Object.listLazyRoutesOfModule (C:\Users\ASUS\Desktop\test1\node_modules\@angular\compiler-cli\src\ngtools_impl.js:53:22)
      at Function.NgTools_InternalApi_NG_2.listLazyRoutes (C:\Users\ASUS\Desktop\test1\node_modules\@angular\compiler-cli\src\ngtool
  s_api.js:91:39)
      at AotPlugin._getLazyRoutesFromNgtools (C:\Users\ASUS\Desktop\test1\node_modules\@ngtools\webpack\src\plugin.js:212:44)
      at _donePromise.Promise.resolve.then.then.then.then.then (C:\Users\ASUS\Desktop\test1\node_modules\@ngtools\webpack\src\plugin
  .js:448:24)
      at process._tickCallback (internal/process/next_tick.js:109:7)</p>
  
  <p>Please can someone tell me what should i do ? i checked other similar questions but i didn't get what i'm supposed to do to solve this problem :x</p>