RN10200 two bays - adding a new drive

That's what I'm seeing in the log tab:

in the right of the screen also there's a feature "registry download"....I clicked on it and the browser downloaded a zip file...I opened it, there's a lot of files inside I can't understand what to search and check.....

Hello Everyone, after reading your suggestions I turned off the nas, extracted the disks one by one and checked with the pc if they had hardware errors, bad blocks, etc., but both disks were healthy.

At this point, I reinserted the two HDDs into the NAS, connected a USB hard drive to one of the NAS USB port and backed up all the data stored on the NAS (during the backup, a couple of files were found to be non-transferable), then I ran on the NAS the factoy default reset process.

After a few hours the NAS had automatically reset all the settings, formatted the disks, created the new array under XRAID by setting the RAID to RAID1 (mirroring.... which was what I wanted).

The shocking thing was that upon completion of the procedure, the NAS was able to see the volume perfectly intact, healty and with no errors of any kind.

Now I have transferred the data from the backup that I had made, back to the NAS and everything is working flawlessly so far.

I keep wondering what went wrong originally, while adding the new HDD, to determine the problem that occurred.

If someone have had a similar experience before and understood what caused the problem that I have also had, I will be happy to have his  opinion.

thanks to everyone who helped me in this forum.