Error with Azure AD B2C federation with Entra ID

PKua, Public domain, via Wikimedia Commons

I was trying to set up the Identity provider in B2C and got this message:

AADB2C: A claim with id 'UserId' was not found, which is required by 
ClaimsTransformation 'CreateAlternativeSecurityId' with 
id 'CreateAlternativeSecurityId'

This made no sense because I had the claims correctly mapped, and I was using “oid” as the “User ID”.

I tried a few things but then added “profile” to the scope, and it all worked!

All good!