Ex2 Ultra no longer 'sees' hard drives

Started last week with a ‘hard drive failure’ message, rebooted the unit but still same message. Replaced the drives with new ones and still the ‘hard drive failure’ message, did the 40 second reset and still the message still appears. Since the OS 5 update I’ve had countless ‘minor’ issues like not accessing it remotely, rebooting every morning etc…

That’s an Ex2 Ultra by the way which never gave Me problems for close to 4 years until OS 5 update.