Why does my device ask for Verification about once a month

Why does my My Cloud Mirror device regularly say that it needs to verify and if you OK it then clears everything and spends up to 2 days rebuilding the backup? Recently I was very busy and dd not want to go through this process for a day or two. During this period my hard drive on my Macbook Po failed and my ‘expert’ says that the storage device seems to be corrupted making it impossible to rebuild the new hard drive. He is laboriously reading data off the disks and copying it manually to the new drive. Sometimes the data moved disappears from the disks and sometimes not and often it says corrupted but can be moved. HELP!

How is your data being extracted from your unit? If you had a RAID 1 array within your WD My Cloud Mirror then one of the internal disk drives should be able to be directly accessible from a Linux-based system with EXT4 file system support. It should be easier than trying to access the whole volume from the enclosure in case it is not working properly.