Oooh, interesting. Thanks for posting the error. That's a new one for me. In any case, it's becoming evident from these responses that I should create a basic tutorial, as well as proper mouse controls. You are correct that the dodge has no i-frames, but that falling down does, like the dive dodge in Monster Hunter if you're familiar with that game. By chance would you happen to remember anything specific about how you were pushing the left stick when you got that error? It'd help me track down what caused that bug. Thanks!
Good to know about the dive. Makes more sense, monster hunter dive is great.
Don't think I was pushing the left stick at all. Just tried again without touching it to be sure and got the same result. Could be something with the pad, stick drifting of some kind. Don't have another to test it with though.