After that, I went to the Zen Cart website to “read the manual,” to see what it had to say about migrating and upgrading. As I expected, there was a lot of information about migrating and upgrading separately, but little to nothing on doing the two simultaneously. However, I did manage to find one article buried somewhere dealing with that issue. Don’t do it, the writer said. Either upgrade first then migrate or migrate first then upgrade; under no circumstances migrate and upgrade at the same time. Too much could go wrong.