I noted that the 'Back' button in both the Import and Export wizard is always greyed out. If one makes a mistake one has to cancel and start over. Isn't this what the 'Back' button should be for, to be able to go back one or more steps in the process?
Yes, ideally we should be able to go back, but the problem here is that a lot has happened in going from the first screen to the second, and its not easy to roll all this back to an intermediate point, so in this specific case we must exclude the option to go back, and this makes it necessary to start again.
It may be posible to fix this in the future, but I'm afraid its not simple to do.