title: TypeError: Cannot read property 'members' of undefined
body: <p>I started upgrading from Angular 4.4.4 to 5.1.1 today. I have had to upgrade a number of other packages that rely on angular as well. I get an error with so little context that I have no idea where to start. Has anyone else seen this and know what the issue is?</p>
  
  <pre><code>$ ng serve --aot=false
  ** NG Live Development Server is listening on localhost:4200, open your browser on http://localhost:4200/ **
  Date: 2017-12-19T15:26:36.137Z
  Hash: bf0b773d5dfafdd9133b
  Time: 16934ms
  chunk {inline} inline.bundle.js (inline) 5.79 kB [entry] [rendered]
  chunk {main} main.bundle.js (main) 2.93 kB [initial] [rendered]
  chunk {polyfills} polyfills.bundle.js (polyfills) 636 bytes [initial] [rendered]
  chunk {scripts} scripts.bundle.js (scripts) 307 kB [initial] [rendered]
  chunk {styles} styles.bundle.js (styles) 4.03 MB [initial] [rendered]
  chunk {vendor} vendor.bundle.js (vendor) 855 kB [initial] [rendered]
  
  ERROR in TypeError: Cannot read property 'members' of undefined
      at AotSummaryResolver.resolveSummary (C:\source\app\node_modules\@angular\compiler\bundles\compiler.umd.js:32638:56)
      at CompileMetadataResolver._loadSummary (C:\source\app\node_modules\@angular\compiler\bundles\compiler.umd.js:14825:66)
      at CompileMetadataResolver._getEntryComponentMetadata (C:\source\app\node_modules\@angular\compiler\bundles\compiler.umd.js:15857:66)
      at C:\source\app\node_modules\@angular\compiler\bundles\compiler.umd.js:15323:55
      at Array.map (&lt;anonymous&gt;)
      at CompileMetadataResolver.getNgModuleMetadata (C:\source\app\node_modules\@angular\compiler\bundles\compiler.umd.js:15323:18)
      at CompileMetadataResolver.getNgModuleSummary (C:\source\app\node_modules\@angular\compiler\bundles\compiler.umd.js:15157:52)
      at C:\source\app\node_modules\@angular\compiler\bundles\compiler.umd.js:15245:72
      at Array.forEach (&lt;anonymous&gt;)
      at CompileMetadataResolver.getNgModuleMetadata (C:\source\app\node_modules\@angular\compiler\bundles\compiler.umd.js:15230:49)
      at visitLazyRoute (C:\source\app\node_modules\@angular\compiler\bundles\compiler.umd.js:31061:104)
      at AotCompiler.listLazyRoutes (C:\source\app\node_modules\@angular\compiler\bundles\compiler.umd.js:31029:20)
      at AngularCompilerProgram.listLazyRoutes (C:\source\app\node_modules\@angular\compiler-cli\src\transformers\program.js:156:30)
      at Function.NgTools_InternalApi_NG_2.listLazyRoutes (C:\source\app\node_modules\@angular\compiler-cli\src\ngtools_api.js:44:36)
      at AngularCompilerPlugin._getLazyRoutesFromNgtools (C:\source\app\node_modules\@ngtools\webpack\src\angular_compiler_plugin.js:248:66)
      at Promise.resolve.then.then (C:\source\app\node_modules\@ngtools\webpack\src\angular_compiler_plugin.js:562:50)
  
  webpack: Failed to compile.
  </code></pre>
  
  <p>I find it strange that it starts in <code>AotSummaryResolver</code> when I have --aot=false in the serve command.</p>
  
  <p>Here is my package.json:</p>
  
  <pre><code>{
    "name": "test",
    "version": "0.0.0",
    "license": "MIT",
    "scripts": {
      "ng": "ng",
      "start": "ng serve --aot=false",
      "build": "ng build",
      "test": "ng test",
      "lint": "ng lint",
      "e2e": "ng e2e"
    },
    "private": true,
    "dependencies": {
      "@agm/core": "^1.0.0-beta.2",
      "@angular-devkit/schematics": "^0.0.42",
      "@angular/animations": "5.1.1",
      "@angular/cdk": "5.0.1",
      "@angular/common": "5.1.1",
      "@angular/compiler": "5.1.1",
      "@angular/core": "5.1.1",
      "@angular/forms": "5.1.1",
      "@angular/http": "5.1.1",
      "@angular/platform-browser": "5.1.1",
      "@angular/platform-browser-dynamic": "5.1.1",
      "@angular/platform-server": "5.1.1",
      "@angular/router": "5.1.1",
      "@auth0/angular-jwt": "^1.0.0-beta.9",
      "@ng-bootstrap/ng-bootstrap": "^1.0.0-beta.8",
      "@ng-idle/core": "^2.0.0-beta.13",
      "@ngrx/core": "^1.2.0",
      "@ngrx/effects": "^4.1.1",
      "@ngrx/entity": "^4.1.1",
      "@ngrx/store": "^4.1.1",
      "@ngrx/store-devtools": "^4.1.1",
      "@schematics/angular": "^0.1.11",
      "@schematics/schematics": "^0.0.11",
      "angular2-counto": "^1.2.3",
      "bootstrap": "4.0.0-beta.2",
      "core-js": "2.4.1",
      "d3": "^4.11.0",
      "echarts": "^3.6.0",
      "echarts-gl": "^1.0.0-alpha.5",
      "font-awesome": "^4.7.0",
      "global": "^4.3.2",
      "intl": "^1.2.5",
      "jquery": "^3.2.1",
      "moment": "^2.19.4",
      "ng2-dnd": "^5.0.2",
      "popper.js": "^1.11.0",
      "roboto-fontface": "^0.7.0",
      "rxjs": "^5.5.2",
      "toastr": "^2.1.2",
      "ts-action": "^3.2.2",
      "typings": "^2.1.1",
      "uuid": "^3.1.0",
      "web-animations-js": "^2.2.5",
      "yarn": "^0.24.5",
      "zone.js": "0.8.4"
    },
    "devDependencies": {
      "@angular/cli": "1.6.1",
      "@angular/compiler-cli": "5.1.1",
      "@types/d3": "^4.11.0",
      "@types/echarts": "^0.0.6",
      "@types/hammerjs": "^2.0.34",
      "@types/jasmine": "2.5.38",
      "@types/jquery": "^2.0.45",
      "@types/node": "^7.0.23",
      "@types/toastr": "^2.1.33",
      "@types/uuid": "^3.4.0",
      "codelyzer": "^4.0.2",
      "jasmine-core": "~2.5.2",
      "jasmine-spec-reporter": "~3.2.0",
      "json-server": "^0.12.0",
      "jsonwebtoken": "^7.4.1",
      "karma": "~1.4.1",
      "karma-chrome-launcher": "~2.1.1",
      "karma-cli": "~1.0.1",
      "karma-coverage-istanbul-reporter": "^0.2.0",
      "karma-jasmine": "~1.1.0",
      "karma-jasmine-html-reporter": "^0.2.2",
      "protractor": "~5.1.0",
      "ts-node": "~2.0.0",
      "tslint": "^5.8.0",
      "typemoq": "^1.7.0",
      "typescript": "2.4.2"
    }
  }
  </code></pre>
  
  <p>My angular-cli version is 1.6.1.</p>
  
  <p>The error seems to occur here in the angular source code:
  <a href="https://github.com/angular/angular/blob/b3eb1db6dd57a0820cfc94af5460ceb3fea20610/packages/compiler/src/aot/summary_resolver.ts#L68" rel="noreferrer">https://github.com/angular/angular/blob/b3eb1db6dd57a0820cfc94af5460ceb3fea20610/packages/compiler/src/aot/summary_resolver.ts#L68</a></p>
  
  <h2>SOLUTION</h2>
  
  <p>Previously I thought it was related to ng-bootstrap which was incorrect.</p>
  
  <p>I found some context for it by putting a console log at line 15207 in compiler.umd.js as follows:</p>
  
  <pre><code>if (meta.entryComponents) {
      console.log(meta);
      entryComponents.push.apply(entryComponents, flattenAndDedupeArray(meta.entryComponents)
                  .map(function (type) { return /** @type {?} */ ((_this._getEntryComponentMetadata(type))); }));
  }
  </code></pre>
  
  <p>Which resulted in:</p>
  
  <pre><code>...
  entryComponents: [ undefined ],
  ...
  </code></pre>
  
  <p>I had a module with <code>entryComponents: [MdProgressSpinner]</code> where <code>MdProgressSpinner</code> was not imported. When I removed it that error went away... and the next one came :)</p>