Slack import fails in Mattermost 1.3?

Here's what I see

$ ./platform -permanent_delete_team -team_name="z-z-zhxacx9i7tfhxqb85pmswwkwrca"
Have you performed a database backup? (YES/NO): YES
Are you sure you want to delete the team z-z-zhxacx9i7tfhxqb85pmswwkwrca?  All data will be permanently deleted? (YES/NO): YES
[01/12/16 10:22:13] [WARN] Attempting to permanently delete team z-z-zhxacx9i7tfhxqb85pmswwkwrca id=11awp31oyir8bmfjhit51ogo6h
[01/12/16 10:22:13] [WARN] Attempting to permanently delete account dyskysawhjytpmutbaoffdmfqwcorey+test@test.com id=1i571dccybnb9cb4fe8osjn5by
[01/12/16 10:22:13] [WARN] Permanently deleted account dyskysawhjytpmutbaoffdmfqwcorey+test@test.com id=1i571dccybnb9cb4fe8osjn5by
[01/12/16 10:22:13] [WARN] Permanently deleted team z-z-zhxacx9i7tfhxqb85pmswwkwrca id=11awp31oyir8bmfjhit51ogo6h