WD My Book WE2 raid1 degraded mode. one disk "unassigned"

WD Legacy Products Other Network Drives
2

The data is still recoverable on RAID 1 as long as the remaining drive does not have problems.

Is the unit still under warranty?

Check the following thread that discuss a similar issue.

http://community.wd.com/t5/Other-Network-Drives/WorldBook-II-Drive-Says-quot-GOOD-quot-But-Clean-HD-Icon-is-On/td-p/188150