This issue duplicates another issue.
app.json generated from SenchaSDKTools-2.0.0-beta3-osx bug
using SenchaSDKTools-2.0.0-beta3-osx to create an app there is a bug in the app.json file:
>sencha app build production
* Build options
"logger": "no" // THIS SHOULD BE false (with no quotes)
otherwise the following error happens upon running:
1. The startup screen hangs and
2. Uncaught Error: [Ext.Loader] Failed loading 'src/log/Logger.js', please verify that the file exists
We already have an internal bug reported for this.