INFO :
-This error is seen after updating mapping in Identityprofile & importing few users in source as flatfile.
-User has already reset the password, still getting the same error.
we have already checked similar posts, but no solution yet
You mentioned about the authoritative source is a csv based sourced, do you know if recently you or anyone else imported new users to the source, there could be a possibility that while importing the new users, this user was not present in the csv file and thus got deleted ( if there is no limit set on deleting accounts on the source) and was reimported back. In that case, i believe you will have to invite the user again.