Welcome! This forum has a treasure trove of great info – Scouters helping Scouters! Just a heads up, though - all content, information, and opinions shared on this forum are those of the author, not the BSA.
I actually think it might be a good thing that it doesn’t let you add a POR to a lapsed Scout because it’ll force you to realize the Scout is lapsed, and the parents will be incentivized to renew.
I do, however, think it would help if an error message popped up telling you why.
The roster will tell you which Scouts are lapsed. The last column gives their expiration date. You can also set your filter like below to see who is in the lapse period.
Thanks. I did see those fields on the roster. I just wasn’t focused on thinking about if that particular Scout’s registration had lapsed when I was trying to update his POR.
But now the next time I’m having issues, I will of course go check the Scouts registration status first thing.