UPDATE:
—I have restored the whole website from the latest backup on the server.
—I am able to access to the WordPress backend now, but it shows up the message to say ERROR 504 – Gateway Time Out on the front end.
Can you please let me know the reason? I thought the restoring of the website would totally 100% revert the site to its latest version?
(I do have contacted the server support and they said the issue is from the theme as they have tested from the PHP version to plugins compatibility, so I kindly come here for any of your advice.)
Thanks n’ Regards
Graham