Cannot read property 'ItemView' of undefined

[matiux]

I have a problem with Marionette application bundled with Webpack.
When I active Marinette Inspector, I get this error:

Uncaught TypeError: Cannot read property 'ItemView' of undefined

agent.js

.............
}(Agent));
;(function(Agent){

  var assignClassNames = function(Backbone, Marionette) {
----->    Marionette.ItemView.prototype._className = 'ItemView';   <-------
    Marionette.CollectionView.prototype._className = 'CollectionView';
    Marionette.CompositeView.prototype._className = 'CompositeView';
    Marionette.View.prototype._className = 'Marionette.View';
.............

Bit the application works

[jasonLaster]

sounds like you need to use

if (window.__agent) {
  window.__agent.start(Backbone, Marionette);
}

[paulfalgout]

possibly related #305

[blikblum]

See caveats section in readme