diff --git a/core/module/config/config.php b/core/module/config/config.php
index ce018ff..f1bb6ed 100644
--- a/core/module/config/config.php
+++ b/core/module/config/config.php
@@ -226,7 +226,7 @@ class config extends common {
 		include('./core/module/config/lang/'. $this->getData(['config', 'i18n', 'langAdmin']) . '/lex_config.php');
 
 		$texte='';
-		if( $_SESSION['screenshot'] === 'on'){
+		if( isset($_SESSION['screenshot']) && $_SESSION['screenshot'] === 'on'){
 			$_SESSION['screenshot'] = 'off';
 			$texte = $text['core_config']['configOpenGraph'][0];
 		}