CiviEvent Wizard going step 3->2->3

When creating a CiviEvent with wizard, moving from step 3 back to 2 then forward to 3 again causes the following error on the demo:
New Event Wizard

unrecoverable error
Sorry. A non-recoverable error has occurred.

Database Error Code: Duplicate entry 'civicrm_event-7-1' for key 2, 1062

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Error Details:

Array
(
[callback] => Array
(
[0] => CRM_Core_Error
[1] => handle
)

[code] => -5
[message] => DB Error: already exists
[mode] => 16
[debug_info] => INSERT INTO civicrm_location (entity_table , entity_id , location_type_id , is_primary , name ) VALUES ('civicrm_event' , 7 , 1 , 0 , 'the bar' ) [nativecode=1062 ** Duplicate entry 'civicrm_event-7-1' for key 2]
[type] => DB_Error
[user_info] => INSERT INTO civicrm_location (entity_table , entity_id , location_type_id , is_primary , name ) VALUES ('civicrm_event' , 7 , 1 , 0 , 'the bar' ) [nativecode=1062 ** Duplicate entry 'civicrm_event-7-1' for key 2]
[to_string] => [db_error: message="DB Error: already exists" code=-5 mode=callback callback=CRM_Core_Error::handle prefix="" info="INSERT INTO civicrm_location (entity_table , entity_id , location_type_id , is_primary , name ) VALUES ('civicrm_event' , 7 , 1 , 0 , 'the bar' ) [nativecode=1062 ** Duplicate entry 'civicrm_event-7-1' for key 2]"]
)