You can clone with
The plugin works well but if something breaks in the code on PHP side no errors or exceptions are thrown. I only get this line from the front-end "SyntaxError: Unexpected token <".
Is there something I can change to make these errors visible so I can debug easier?
If you get this error, simply check the server response in the network tab of your browser development tools, e.g. Firebug or Chrome's Dev Tools.
There you can see the complete PHP error message.