Please enable to restore course with users who have firstaccess=0 attribute, of both backup file and alive user has firstaccess=0.
Currently, there is a validation before restoration and if an alive user has firstaccess=0, than it will break restoration (backup originating from different moodle instances).
We have semesters at our university and need to archive semesters into a different moodle instance (dedicated for archiving). Users are registered and enrolled based on an external system, so it's a valid case that a user has been created and enrolled to a course, but does not visits moodle site ever. Then restoration will fail on archive instance, as user has firstaccess=0 at both instances (and in backup) as well. If user was enrolled only for a single course, then it's not an issue, as user will be created automatically, but if there is a secondary course enrollment, then restoration will fail. We have a high amount of courses to archive, so enditing backup file and distinct users is not a viable solution.