diff --git a/resources/inc/class.resources_ui.inc.php b/resources/inc/class.resources_ui.inc.php
index a4ad9cfff3..ccf0f60389 100755
--- a/resources/inc/class.resources_ui.inc.php
+++ b/resources/inc/class.resources_ui.inc.php
@@ -476,11 +476,11 @@ class resources_ui
 		}
 
 		$nm_session_data = Api\Cache::getSession('resources', 'index_nm');
-		$res_id = is_numeric($content) ? (int)$content : $content['res_id'];
+		$res_id = is_scalar($content) && is_numeric($content) ? (int)$content : $content['res_id'];
 		if (isset($_GET['res_id'])) $res_id = $_GET['res_id'];
 		if (isset($nm_session_data['filter2']) && $nm_session_data['filter2'] > 0) $accessory_of = $nm_session_data['filter2'];
 		if (isset($_GET['accessory_of'])) $accessory_of = $_GET['accessory_of'];
-		$content = $content ?? array('res_id' => $res_id);
+		$content = is_array($content) ? $content : array('res_id' => $res_id);
 		if ($res_id > 0)
 		{
 			$content = array_merge($this->bo->read($res_id), $content);
@@ -588,5 +588,4 @@ class resources_ui
 		return $this->tmpl->exec('resources.resources_ui.edit',$content,$sel_options,$read_only,$preserv,2);
 	}
 
-}
-
+}
\ No newline at end of file