prevent errors if menu is not defined

index.php

@@ -17,6 +17,10 @@ $f3->set('UI', implode(';',array(
     ROOT.'content/' // content folders can contain .html templates
 )));
 
+if(!is_dir($f3->get('TEMP'))) {
+    mkdir($f3->get('TEMP'));
+}
+
 
 
 /////////////////////////
@@ -71,12 +75,14 @@ if(array_key_exists($f3->get('LANG'), $f3->get('nav.network'))) {
 } else {
   $menu=$f3->get('nav.network.'.$f3->get('default_lang'));
 }
-foreach($menu as $k=>$v) {
-    $ex = explode(": ", $menu[$k]);
-    $menu[$k] = array(
-        'name' => trim($ex[0]),
-        'href' => count($ex) > 1 ? $ex[1] : $ex
-    );
+if(is_array($menu)) {
+    foreach($menu as $k=>$v) {
+        $ex = explode(": ", $menu[$k]);
+        $menu[$k] = array(
+            'name' => trim($ex[0]),
+            'href' => count($ex) > 1 ? $ex[1] : $ex
+        );
+    }
 }
 $f3->set('navi.network._config.addHome', $f3->get('nav.network.config.addHome'));
 $f3->set('navi.network', $menu);