peter I guess my wording wasn't terribly exact. I did purchase licenses for both ST3 and then later, ST4. I had searched on the topic and found older references where you appeared to suggest going from ST3 first if having trouble with ST4. I should not have mentioned that as it only confused the matter.
Let me try and re-state this more accurately. My wife's ipad is already logged in as her in icloud. As you know, when one goes to the app store the system already knows that. So when I downloaded/installed ST4 by itself (no version of StageTraxx on the machine) it allows you to do that easily. But when I started up ST4 and went to the license page and tried to 'restore previous purchase', it automatically asked for the apple password for my wife (as one would expect). So it's been my wife's account (icloud family member of mine) that is assumed as password request pops up. I then put in her apple password but that never results in the license upgrade taking place. It just goes back to the screen asking if you want to purchase, with the same option to 'restore prior purchase' still available. Added note: the apple ID & password request that comes up cannot be changed. Only option is to enter the password - period.
I hope this explanation of circumstances is sufficient to make a determination as to whether this has a chance of working. (BTW, I've checked and rechecked, re-tried and re-tried, the password for her Apple ID. We use LastPass so there's little chance of error as to what the usernames or passwords are.
Thanks,
Chris