title: how to find "illegal literal map"
body: <p>I am in the process of migrating an application to Angular 6 from Angular 5. at this point I believe I have most issues sorted out and when building with <code>ng serve</code> or <code>ng build main</code> it builds as expected. however when building as <code>ng build --prod main</code> I get the below error</p>
  
  <pre><code>ERROR in : Error: Illegal State: literal maps should have been converted into functions
      at _AstToIrVisitor.visitLiteralMap (/workspace/tarnished-lamp/node_modules/@angular/compiler/bundles/compiler.umd.js:15824:19)
      at LiteralMap.visit (/workspace/tarnished-lamp/node_modules/@angular/compiler/bundles/compiler.umd.js:3483:28)
      at ASTWithSource.visit (/workspace/tarnished-lamp/node_modules/@angular/compiler/bundles/compiler.umd.js:3598:29)
      at convertPropertyBinding (/workspace/tarnished-lamp/node_modules/@angular/compiler/bundles/compiler.umd.js:15626:52)
      at createHostBindingsFunction (/workspace/tarnished-lamp/node_modules/@angular/compiler/bundles/compiler.umd.js:20068:39)
      at baseDirectiveFields (/workspace/tarnished-lamp/node_modules/@angular/compiler/bundles/compiler.umd.js:19754:43)
      at compileComponentFromMetadata (/workspace/tarnished-lamp/node_modules/@angular/compiler/bundles/compiler.umd.js:19793:29)
      at compileComponentFromRender2 (/workspace/tarnished-lamp/node_modules/@angular/compiler/bundles/compiler.umd.js:19878:19)
      at /workspace/tarnished-lamp/node_modules/@angular/compiler/bundles/compiler.umd.js:21551:21
      at Array.forEach (&lt;anonymous&gt;)
      at AotCompiler._compilePartialModule (/workspace/tarnished-lamp/node_modules/@angular/compiler/bundles/compiler.umd.js:21527:24)
      at /workspace/tarnished-lamp/node_modules/@angular/compiler/bundles/compiler.umd.js:21509:58
      at Array.forEach (&lt;anonymous&gt;)
      at AotCompiler.emitAllPartialModules (/workspace/tarnished-lamp/node_modules/@angular/compiler/bundles/compiler.umd.js:21509:19)
      at AngularCompilerProgram._emitRender3 (/workspace/tarnished-lamp/node_modules/@angular/compiler-cli/src/transformers/program.js:252:41)
      at AngularCompilerProgram.emit (/workspace/tarnished-lamp/node_modules/@angular/compiler-cli/src/transformers/program.js:235:59)
  </code></pre>
  
  <p>I have two questions from this</p>
  
  <ol>
  <li>What does this Error actually mean</li>
  <li>How do I find it and correct it</li>
  </ol>