Recovery my files of a old hard disk

My Cloud OS 3 Personal & Network Attached Storage My Cloud EX2
1

Hi,

I bought 2x8TB new hard disk to create a RAID 1 of 8TB in my Ex2 Ultra. I had problems during the process of copy the files and I need reinstall 1 of old disk in NAS.

I have 1 of the old 2TB disks that I extracted but now my Ex2 Ultra can’t recognize this drive.

How can I access to the information of this disk?

Thank you.