handle non existing lang file

classes/cronlog.class.php

@@ -79,6 +79,11 @@ class cronlog {
             $this->_aInstances = isset($aCfgTemp['instances']) ? $aCfgTemp['instances'] : [];
 
             $this->_sLang=isset($aCfgTemp['lang']) && $aCfgTemp['lang'] ? $aCfgTemp['lang'] : 'en-en';
+            if(!file_exists(__DIR__.'/../config/lang_'.$this->_sLang.'.php')){
+                header('HTTP/1.1 503 Service Temporarily Unavailable');
+                header('Status: 503 Service Temporarily Unavailable');
+                die('ERROR: lang file for lang => "'.$this->_sLang.'" not found.<br>config/lang_'.$this->_sLang.'.php<br>does not exist.');
+            }
             $this->_aLang=$aCfgTemp=include(__DIR__.'/../config/lang_'.$this->_sLang.'.php');
         }
         $this->_sDataDir = str_replace("__APPDIR__", dirname(dirname(__FILE__)), $this->_sDataDir);