Index: t3lib/class.t3lib_div.php
===================================================================
--- t3lib/class.t3lib_div.php	(revision 3117)
+++ t3lib/class.t3lib_div.php	(working copy)
@@ -3894,6 +3894,9 @@
 							// Read and parse XML content:
 						$local_xmlString = t3lib_div::getUrl($localized_file);
 						$local_xmlContent = t3lib_div::xml2array($local_xmlString);
+						if (!is_array($local_xmlContent))	{
+							die('\''.$localized_file.'\' is no TYPO3 language file)!');
+						}
 						$LOCAL_LANG[$langKey] = is_array($local_xmlContent['data'][$langKey]) ? $local_xmlContent['data'][$langKey] : array();
 
 							// Checking if charset should be converted.