App crashed when deployed to Heroku

[alelordelo]

Do you know what could be the issue?

$ heroku logs -t -a tstudio
2016-12-06T22:07:25.937574+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=tstudio.herokuapp.com request_id=93505154-e7c1-412e-aa32-bb0a9bb19271 fwd="152.179.69.246" dyno= connect= service= status=503 bytes=
2016-12-06T22:07:27.133204+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=tstudio.herokuapp.com request_id=236e13ef-1e4e-4f13-ae1d-58d02bac5208 fwd="152.179.69.246" dyno= connect= service= status=503 bytes=