Fix WordPress Critical Error -- 2

Job ID: 39961789

Budget: £20 – £250 GBP

My WordPress site is down and showing the “There has been a critical error on this website” message. The issue appeared without an obvious trigger, so I’m unsure whether it stems from a silent update or a hidden conflict. I have already tried deactivating plugins via wp-admin and FTP, but the error persists.

I need someone who can:
• Trace the underlying cause of the fatal error (PHP logs, WP_DEBUG, server error logs).
• Restore full front-end and back-end functionality without data loss.
• Explain what happened and outline clear prevention steps (e.g., plugin/theme conflict report, version compatibility notes).

Access I can provide: cPanel, FTP/SFTP, phpMyAdmin, and WordPress admin.
Time is important—please let me know how soon you can begin and how long you expect the fix to take. A concise post-repair summary is part of the deliverable so I understand the solution applied.