DB constraint error

When all 100 default contacts are selected, and an attempt is made to delete them, the following error occurred:

Sorry. A non-recoverable error has occurred.

Database Error Code: Cannot add or update a child row: a foreign key constraint fails, 1216

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error

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

[code] => -3
[message] => DB Error: constraint violation
[mode] => 16
[debug_info] => INSERT INTO civicrm_log (entity_table , entity_id , modified_id , modified_date ) VALUES ('civicrm_household' , 12 , 101 , 20060804144114 ) [nativecode=1216 ** Cannot add or update a child row: a foreign key constraint fails]
[type] => DB_Error
[user_info] => INSERT INTO civicrm_log (entity_table , entity_id , modified_id , modified_date ) VALUES ('civicrm_household' , 12 , 101 , 20060804144114 ) [nativecode=1216 ** Cannot add or update a child row: a foreign key constraint fails]
[to_string] => [db_error: message="DB Error: constraint violation" code=-3 mode=callback callback=CRM_Core_Error::handle prefix="" info="INSERT INTO civicrm_log (entity_table , entity_id , modified_id , modified_date ) VALUES ('civicrm_household' , 12 , 101 , 20060804144114 ) [nativecode=1216 ** Cannot add or update a child row: a foreign key constraint fails]"]
)