Import Demo Data: Import Failed – Vũ Duy Hùng

Hi, I’m try to Import demo data but “Import Failed” with “Error: error (503)”. And: Deprecated: Creation of dynamic property Wiso_Plugins::$assets_css is deprecated in /home/itlzucwehosting/public_html/wp-content/plugins/wiso-plugins/register_post_types.php on line 12 Deprecated: Creation of dynamic property Appsero\Updater::$cache_key is deprecated in /home/itlzucwehosting/public_html/wp-content/themes/wiso/vendor/appsero/client/src/Updater.php on line 26 What should I do? Thanks for helping