Q. I got an error message that all the licensed copies of an ebook are in use. What do I do?
This means that this particular ebook has a limit to how many people can read it at a time and currently that many people are reading it. (It's like when all the copies of a physical reserve book are checked out.) Work on something else for a little while and then come back and try again.
If it keeps giving you a weird message please contact the Reference Desk!