diff --git a/functions.php b/functions.php
index 128f260..4d6ebcd 100644
--- a/functions.php
+++ b/functions.php
@@ -1952,6 +1952,9 @@ function shorten($text, $count = '55') {
 }
 
 
+// define( 'WP_DEBUG', true );
+// define( 'WP_DEBUG_LOG', true );
+
 /**
  * Debug Function
  *
@@ -3268,21 +3271,24 @@ function qp_translate_theme() {
  * @return string browser language
  */
 function qp_detect_browser_language() {
-	$browser_language = substr($_SERVER['HTTP_ACCEPT_LANGUAGE'], 0, 5);
-	if(stripos($browser_language, "de") !== false ){
-		return "de_DE";
-	}elseif(stripos($browser_language, "it") !== false ){
-		return "it_IT";
-	}elseif(stripos($browser_language, "tr") !== false ){
-		return "tr_TR";
-	}elseif(stripos($browser_language, "en") !== false ){
-		return "en_GB";
-	}
-	else{
+	if (isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {
+		$browser_language = substr($_SERVER['HTTP_ACCEPT_LANGUAGE'], 0, 5);
+		if(stripos($browser_language, "de") !== false ){
+			return "de_DE";
+		}elseif(stripos($browser_language, "it") !== false ){
+			return "it_IT";
+		}elseif(stripos($browser_language, "tr") !== false ){
+			return "tr_TR";
+		}elseif(stripos($browser_language, "en") !== false ){
+			return "en_GB";
+		}
+		else{
+			return "de_DE";
+		}
+	} else {
 		return "de_DE";
 	}
 }
-
 /**
  * QP language function
  * 
diff --git a/header.php b/header.php
index f083687..1ec84fd 100644
--- a/header.php
+++ b/header.php
@@ -173,7 +173,6 @@
     <meta property="og:locale:alternate" content="it_IT" />
     <meta property="og:site_name" content="<?php echo 'Quartiersplattform '.get_field('quartiersplattform-name','option'); ?>"/>
     <meta name="twitter:card" content="summary"/>
-    <!-- <meta name="twitter:site" content="<?php echo esc_attr( $twitter_site ); ?>"/> -->
 
     <!-- Matomo Tracking API Key -->
     <?php the_field('matomo_api', 'option'); ?>