“Hmmm. I don’t know that one.” or “Hmmm. I have a few skills that can help.”

This is often the response when you are attempting to launch a skill, but the given invocation name doesn’t match the skill’s invocation name. While Alexa is very good at matching sample utterances to spoken utterances, even if they’re not exactly the same, the invocation name must be given precisely as it is defined in the interaction model.

For example, if you were to say, “Alexa, open Star Port Seventy Five,” but the skill’s invocation name is “Star Port Seventy Five Travel”, then Alexa won’t know for sure what skill it is that you’re trying to launch. If she can find a similarly named skill, she will offer that as a suggestion. Otherwise, she’ll say that she doesn’t “know that one.”