When a user tries to update their profile they will get a message to pay attention to a field which is the Perma-Link field. If they have set a permalink like I did with Sean-Carney then they have to REMOVE the Perma-Link to save their Profile changes. Afterwards they can immediately add back the Perma-Link.
I am seeing this at
https://www.Starch-Smart.com
By the way, the reason I discovered this is because I added a Terms of Service to the registration and made it mandatory. But, a few users had been created before that point. So, when I turned on the function to remind people if their profiles are not complete I discovered that my account and some of the earlier users needed to be updated. However, we had perma-links and they prevented us from being able to save the profiles.