Index: branches/5.2.x/core/units/languages/languages_event_handler.php
===================================================================
--- branches/5.2.x/core/units/languages/languages_event_handler.php
+++ branches/5.2.x/core/units/languages/languages_event_handler.php
@@ -96,6 +96,8 @@
 
 				$this->Application->SetVar('m_lang', $language_id);
 				$this->Application->SetVar($event->getPrefixSpecial() . '_id', $language_id);
+
+				return $language_id;
 			}
 
 			return parent::getPassedID($event);
Index: branches/5.2.x/core/units/themes/themes_eh.php
===================================================================
--- branches/5.2.x/core/units/themes/themes_eh.php
+++ branches/5.2.x/core/units/themes/themes_eh.php
@@ -87,6 +87,8 @@
 
 				$this->Application->SetVar('m_theme', $theme_id);
 				$this->Application->SetVar($event->getPrefixSpecial() . '_id', $theme_id);
+
+				return $theme_id;
 			}
 
 			return parent::getPassedID($event);