Cannot add or update a child row: a foreign key constraint fails

[ext]

Fatal error: Uncaught exception 'Exception' with message 'Internal error, failed to execute query:

INSERT INTO `deliveries` SET
`description` = ?,
`user_id` = ?
Cannot add or update a child row: a foreign key constraint fails (`nx17_retail`.`deliveries`, CONSTRAINT `deliveries_ibfk_1` FOREIGN KEY (`user_id`) REFERENCES `users` (`user_id`))

' in /var/www-kiosk/classes/BasicObject.php:314 Stack trace:
#0 /var/www-kiosk/controllers/Delivery.php(38): BasicObject->commit() #1 /var/www-kiosk/classes/Controller.php(104): DeliveryC->make(Array)
#2 /var/www-kiosk/classes/Controller.php(128): Controller::_stack('Delivery/make', Array, 'add')
#3 /var/www-kiosk/public/index.php(17): Controller::_declare('Delivery/make', Array)
#4 {main} thrown in /var/www-kiosk/classes/BasicObject.php on line 314 

[edruid]

My guess would be that the user "logged in" doesn't actually exist. Have you reseted your database after logging in?

[ext]

Database was reset, user logged out and relogged in. Is the session cleared properly? Issue went away after a couple of attempts.