title: ERROR in Cannot read property 'flags' of undefined
body: <p>When I run ng serve , I get the following error </p>
  
  <pre><code>chunk {main} main.js, main.js.map (main) 2.2 kB [initial] [rendered]
  chunk {polyfills} polyfills.js, polyfills.js.map (polyfills) 673 bytes [initial] [rendered]
  chunk {polyfills-es5} polyfills-es5.js, polyfills-es5.js.map (polyfills-es5) 518 kB [initial] [rendered]
  chunk {runtime} runtime.js, runtime.js.map (runtime) 6.15 kB [entry] [rendered]
  chunk {styles} styles.js, styles.js.map (styles) 2.31 MB [initial] [rendered]
  chunk {vendor} vendor.js, vendor.js.map (vendor) 341 kB [initial] [rendered]
  Date: 2020-02-20T13:02:31.697Z - Hash: 338163632aa756e7ed60 - Time: 29669ms
  ERROR in Cannot read property 'flags' of undefined
  </code></pre>
  
  <p>I have tried so many things like  npm update,    ng build. But nothing is working.
  I get the following message on the browser,
  Cannot GET /</p>
  
  <hr>
  
  <p>Executing ng --version 
  gives the following output</p>
  
  <pre><code>Angular CLI: 9.0.3
  Node: 10.15.0
  OS: win32 x64
  
  Angular: 9.0.2
  ... animations, common, compiler, compiler-cli, core, forms
  ... language-service, platform-browser, platform-browser-dynamic
  ... router
  Ivy Workspace: Yes
  
  Package                           Version
  -----------------------------------------------------------
  @angular-devkit/architect         0.900.3
  @angular-devkit/build-angular     0.900.3
  @angular-devkit/build-optimizer   0.900.3
  @angular-devkit/build-webpack     0.900.3
  @angular-devkit/core              9.0.3
  @angular-devkit/schematics        9.0.3
  @angular/cdk                      9.0.1
  @angular/cli                      9.0.3
  @angular/http                     7.2.16
  @angular/material                 9.0.1
  @ngtools/webpack                  9.0.3
  @schematics/angular               9.0.3
  @schematics/update                0.900.3
  rxjs                              6.5.4
  typescript                        3.7.5
  webpack                           4.41.6
  
  </code></pre>
  
  <p>Pl help</p>
  
  <p>Regards,</p>