Here's a dilemma. Software changes are a constant issue when it comes to teaching classes on the software. What do you do when there is no textbook available for the current version of the software, and the changes are enough to make the old text no longer valid? The manufacturer publishes one, but the cost is prohibitive. So we don't make it part of class requirements. My current solution is to use the old one, and caution the students that there are changes, and to note where those are. I am open to a better suggestion.