WordPress Site Critical Error Resolution

I have an existing WordPress website hosted with HostGator that is currently down and displaying the message: **“There has been a critical error on this website.”** The domain and hosting are both active, so this appears to be a WordPress/PHP issue... (Budget: $10 - $30 AUD, Jobs: cPanel, Database Management, HTML, PHP, Web Development, Web Hosting, Website Design, Website Management, Website Optimization, WordPress)