Unable to create Scheduled Task for domain in Plesk: Call to a member function getDomain() on null.

Symptoms

• Unable to create Scheduled Tasks for domain:

  PLESK_ERROR: Error: Call to a member function getDomain() on null 

• The following error is found in /var/log/plesk/panel.log:

  CONFIG_TEXT: PHP Warning:  Undefined array key 339 in /usr/local/psa/admin/plib/CommonPanel/Form/Scheduler/Task.php on line 533
  ERR [panel] Call to a member function getDomain() on null:
  0: /usr/local/psa/admin/plib/CommonPanel/Form/Scheduler/Task.php:534
  CommonPanel_Form_Scheduler_Task->processForm()
  1: /usr/local/psa/admin/plib/CommonPanel/Controller/Action/Scheduler/Trait.php:197
  Smb_SchedulerController->_formTaskAction(object of type Db_Table_Row_ScheduledTask, boolean true)
  2: /usr/local/psa/admin/plib/CommonPanel/Controller/Action/Scheduler/Trait.php:159
  Smb_SchedulerController->addTaskAction()
  3: /usr/local/psa/admin/plib/vendor/plesk/zf1/library/Zend/Controller/Action.php:516
  Zend_Controller_Action->dispatch(string 'addTaskAction')
  4: /usr/local/psa/admin/plib/vendor/plesk/zf1/library/Zend/Controller/Dispatcher/Standard.php:308
  Zend_Controller_Dispatcher_Standard->dispatch(object of type Zend_Controller_Request_Http, object of type Zend_Controller_Response_Http)
  5: /usr/local/psa/admin/plib/vendor/plesk/zf1/library/Zend/Controller/Front.php:954
  Zend_Controller_Front->dispatch(object of type Zend_Controller_Request_Http)
  6: /usr/local/psa/admin/plib/Application/Web.php:48

• The Plesk version is 18.0.67.1 

Cause

Bug with ID #PPPM-14812. The bugfix is released in Plesk version 18.0.67.2.

Resolution

Update Plesk.