* Fix the error if the object does not exist.

module/task/control.php

@@ -537,7 +537,7 @@ class task extends control
         }
 
         $changes = $this->task->deleteWorkhour($effortID);
-        if(dao::isError()) return $this->send(array('result' => 'fail', 'message' => dao::getError()));
+        if(dao::isError() || empty($changes)) return $this->send(array('result' => 'fail', 'message' => dao::getError()));
 
         $actionID = $this->loadModel('action')->create('task', $taskID, 'DeleteEstimate');
         $this->action->logHistory($actionID, $changes);

module/task/model.php

@@ -1789,13 +1789,19 @@ class taskModel extends model
      *
      * @param  int    $effortID
      * @access public
-     * @return void
+     * @return array|false
      */
     public function deleteWorkhour(int $effortID)
     {
         $effort = $this->getEffortByID($effortID);
-        $task   = $this->getById($effort->objectID);
-        $now    = helper::now();
+        if(empty($effort))
+        {
+            dao::$errors[] = $this->lang->notFound;
+            return false;
+        }
+
+        $task = $this->getById($effort->objectID);
+        $now  = helper::now();
 
         /* Compute the left and consumed workhour of the task. */
         $consumed = $task->consumed - $effort->consumed;