Resolution: Not a bug
Affects Version/s: 1.8.13, 1.9.10
Fix Version/s: None
Affected Branches:MOODLE_18_STABLE, MOODLE_19_STABLE
when I backup and restore a course with userdata I'll get this error:
Trying to restore user 'guest' from backup file will cause conflict
My workaround: edit moodle.xml and delete the User>Guest-Part...
(happens even if no guest-user-access is allowed)