DeprecationWarning: The truth value of an empty array is ambiguous. Returning False, but in future this will result in an error. Use `array.size > 0` to check that an array is not empty

Rasa Open Source
2

What exactly are you doing? If you search for the error, you will find a couple of explanations, e.g. python - sklearn DeprecationWarning truth value of an array - Stack Overflow