Why does upgrading require license re-assignment?

[MNBlockHead]

I'm in the middle of a convention. Played in an Adventurer's League game with a new character that also leveled up. Plan to play again tomorrow.

Came home and fired up hero labs and sow that there was a new version. I downloaded and installed. After installing I prompts me for a license reassignment.

And, as I type this, I realize that on Friday I upgraded my laptop from Windows 10 home to Windows 10 Pro. Would that cause HL to treat my laptop, that already has HL installed on it as a new computer?

I'm guessing that is what happened. Man, this sucks big time. I can't save or print characters now. Looks like I'm stuff with the gimped trial version until Monday at the earliest.

Any way around this? Hating myself for upgrading on weekend. Should have learned by now, NEVER upgrade RW or HL within three business days of a game day. Ugh.