title: Error initializing GroovyPageView
body: <p>I am using <code>grails 2.3.4</code>. When I load my index.gsp page I get:</p>
  
  <pre><code>| Server running. Browse to http://localhost:8080/testApplication
  | Application loaded in interactive mode. Type 'stop-app' to shutdown.
  | Enter a script name to run. Use TAB for completion:
  ....[/testApplication].[gsp] Servlet.service() for servlet [gsp] in context w
  ith path [/testApplication] threw exception
  org.codehaus.groovy.grails.web.mapping.exceptions.UrlMappingException: Error map
  ping onto view [/index]: Error initializing GroovyPageView
          at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.
  java:1145)
          at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor
  .java:615)
          at java.lang.Thread.run(Thread.java:744)
  Caused by: java.lang.RuntimeException: Error initializing GroovyPageView
          ... 3 more
  Caused by: org.codehaus.groovy.grails.web.taglib.exceptions.GrailsTagException:
  Expecting '=' after attribute name (ng-app).
          ... 3 more
  [/testApplication].[gsp] Servlet.service() for servlet [gsp] in context with
  path [/testApplication] threw exception
  org.codehaus.groovy.grails.web.mapping.exceptions.UrlMappingException: Error map
  ping onto view [/index]: Error initializing GroovyPageView
          at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.
  java:1145)
          at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor
  .java:615)
          at java.lang.Thread.run(Thread.java:744)
  Caused by: java.lang.RuntimeException: Error initializing GroovyPageView
          ... 3 more
  Caused by: org.codehaus.groovy.grails.web.taglib.exceptions.GrailsTagException:
  Expecting '=' after attribute name (ng-app).
          ... 3 more
  [/testApplication].[gsp] Servlet.service() for servlet [gsp] in context with
  path [/testApplication] threw exception
  org.codehaus.groovy.grails.web.mapping.exceptions.UrlMappingException: Error map
  ping onto view [/index]: Error initializing GroovyPageView
          at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.
  java:1145)
          at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor
  .java:615)
          at java.lang.Thread.run(Thread.java:744)
  Caused by: java.lang.RuntimeException: Error initializing GroovyPageView
          ... 3 more
  Caused by: org.codehaus.groovy.grails.web.taglib.exceptions.GrailsTagException:
  Expecting '=' after attribute name (ng-app).
          ... 3 more
  </code></pre>
  
  <p>My <code>index.gsp</code> looks simple:</p>
  
  <pre><code>&lt;head ng-app&gt; 
  &lt;meta name="layout" content="main" /&gt;
  &lt;title&gt;Title Page&lt;/title&gt;
  
  &lt;!-- here we are loading angularjs --&gt;
  &lt;r:require module="angular" /&gt;
  
  &lt;/head&gt;
  &lt;body&gt;
      &lt;div&gt;
          &lt;div&gt;Hello World!&lt;/div&gt;
          &lt;p&gt;Nothing here {{'yet' + '!'}}&lt;/p&gt;
          &lt;p&gt;1 + 2 = {{ 1 + 2 }}&lt;/p&gt;
      &lt;/div&gt;
  &lt;/body&gt;
  </code></pre>
  
  <p>and my <code>URL mapping</code> looks like that:</p>
  
  <pre><code>class UrlMappings {
  
      static mappings = {
          "/api/product"(resources:"product")
          "/$controller/$action?/$id?(.${format})?"{
              constraints {
                  // apply constraints here
              }
          }
  
          "/"(view:"/index")
          "500"(view:'/error')
  
      }
  }
  </code></pre>
  
  <p>Why do I get this error?
  I really appreciate your answer! </p>
  
  <p><strong>UPDATE</strong></p>
  
  <p>My <code>ApplicationResources.groovy</code> file:</p>
  
  <pre><code>modules = {
  
      'angular' {
          resource url:'/js/lib/angular-1.2.8/angular.min.js'
          resource url:'/js/lib/angular-1.2.8/angular-resource.min.js'
          println "Loading libs"
      }
  
  }
  </code></pre>
  
  <p>Thats my folder structure:</p>
  
  <p><img src="https://i.stack.imgur.com/gQEYq.jpg" alt="enter image description here"></p>