Index: branches/5.2.x/core/units/scheduled_tasks/scheduled_task_eh.php
===================================================================
--- branches/5.2.x/core/units/scheduled_tasks/scheduled_task_eh.php
+++ branches/5.2.x/core/units/scheduled_tasks/scheduled_task_eh.php
@@ -289,10 +289,15 @@
 		{
 			parent::OnAfterConfigRead($event);
 
+			// Don't initialize 'scheduled-task' unit, because scheduled tasks are not run during install.
+			if ( defined('IS_INSTALL') && IS_INSTALL ) {
+				return;
+			}
+
 			$cron_helper = $this->Application->recallObject('kCronHelper');
 			/* @var $cron_helper kCronHelper */
 
 			$cron_helper->initUnit($event->Prefix, 'RunSchedule');
 
 		}
-	}
\ No newline at end of file
+	}