-Convert scene to corona
^ do you mean using the Corona Converter script?
Yes. Not that it's necessary for it to crash though. That's what I did in my test. Instead of changing the render engine in the actual render dialogue menu, I just use the script.
-start interactive render
^ docked or floating?
Floating.
-license required
^ the thing is that after activating Corona once, it should not ask for activation again. That's why I suggested clearing the licensing files in %localappdata%
If that does not help, I am not really sure what may be happening. What happens if you activate Corona first, and only then start IR?
Corona asks for the license approximately once a month. That's why I'm not freaking out about this bug. I just thought reporting it anyway.
So if it'll take you unnecessary time, don't worry about it. It's fine for me to just use a workaround.