Problema ao tentar inserir novo RSS

*** PHP Deprecated function(8192): array_key_exists(): Using array_key_exists() on objects is deprecated. Use isset() or property_exists() instead
Backtrace :
:
...zend-i18n\src\Translator\Loader\Gettext.php:142 array_key_exists()
...ork\zend-i18n\src\Translator\Translator.php:700 Zend\I18n\Translator\Loader\Gettext->load()
...ork\zend-i18n\src\Translator\Translator.php:572 Zend\I18n\Translator\Translator->loadMessagesFromFiles()
...ork\zend-i18n\src\Translator\Translator.php:440 Zend\I18n\Translator\Translator->loadMessages()
...ork\zend-i18n\src\Translator\Translator.php:388 Zend\I18n\Translator\Translator->getTranslatedMessage()
inc\autoload.function.php:171 Zend\I18n\Translator\Translator->translatePlural()
inc\rssfeed.class.php:85 _n()
inc\commondbtm.class.php:2330 RSSFeed::getTypeName()
inc\rssfeed.class.php:646 CommonDBTM->showFormHeader()
inc\commonglpi.class.php:467 RSSFeed->showForm()
ajax\common.tabs.php:97 CommonGLPI::displayStandardTab()