title: autodesk forge viewer.js update from 6.5.1 to 6.6 or 7.1, 2d hyperlink promise exception
body: <p>change view from 3d to 2d view.<br/>
  In 6.5.1 <br/>
   viewer.load(document.getViewablePath(Views2D));<br/>
   no exception<br/>
  In 6.6<br/>
   viewer.load(document.getViewablePath(Views2D)); <br/>
  //promise exception in chrome console<br/>
  In 7.1<br/>
   viewer.loadModel(document.getViewablePath(Views2D), {});<br/>
  //promise exception in chrome console<br/></p>
  
  <pre>
  <code>
  
      Uncaught (in promise) 
      {instanceTree: null, maxTreeDepth: 0, err: undefined}
      Promise.then (async)        
      loadHyperlinks  @   HyperlinkTool.js:323
      activate    @   HyperlinkTool.js:123
      activateTool    @   ToolController.js:265
      f.load  @   Hyperlink.js:42
      loadExtensionLocal  @   ExtensionManager.js:270
      loadExtension   @   ExtensionManager.js:213
      (anonymous) @   ExtensionManager.js:312
      o.onload    @   globals.js:183
      load (async)        
      u   @   globals.js:185
      (anonymous) @   ExtensionManager.js:310
      loadExtensionAsync  @   ExtensionManager.js:309
      loadExtension   @   ExtensionManager.js:205
      (anonymous) @   GuiViewer3D.js:412
      setTimeout (async)      
      D.createUI  @   GuiViewer3D.js:406
      (anonymous) @   GuiViewer3D.js:300
      (anonymous) @   GuiViewer3D.js:288
      setTimeout (async)      
      (anonymous) @   GuiViewer3D.js:316
      (anonymous) @   Viewer3D.js:1228
      (anonymous) @   F2DLoader.js:420
  
  </code>
  </pre>