There is probably some dependency on your app that is not being loaded and thus generating an error and stopping the correct app loading.
If your application performs ajax requests, it is possible that it is capturing a 404 response when trying to execute such requests. This problem is solved by installing the Cordova-Whitelist-plugin.
I recommend that you list the plugins of Cordova installed in your application by typing in the terminal: cordova plugin list
or ionic plugin list
. Most Cordova plugins must be registered in the app.js in order to be loaded by Ionic.
Finally, there is the option for you to simulate your application on an android or iOS device and use a monitoring to check the error log.
If your device is android just plug an android device into the USB and run the command monitor
which is inside the Android SDK.
If your device is iOS, just use Xcode.