Bruce has a network attached storage (NAS) drive and he's getting an error message. He's worried he's lost the data. Leo says that if the network RAID was set to RAID 0 or "scary RAID" then there's a chance that's the case. But if it was set as "redundant" then if one drive has gone bad, replacing it will fix it. The error message Bruce is getting indicates the entire Western Digital NAS has been corrupted and the only thing he can do is reboot the NAS and see if it self-corrects. Bruce also said that the error occurred with all the drives taken out of the machine. Leo says that could indicate a hardware error, or it could indicate that the NAS gives that error without drives.
Bruce could maybe get a duplicate enclosure and put the drives into them and see if they work. If so, he'll know the enclosure failed. That may cost him, but since it's an older model, he could get one on eBay affordably. He should figure out which drive went bad and replace it. See if it boots. This is why an off-site backup is so important. A NAS isn't a backup if he doesn't have the files anywhere else. Leo also recommends getting a Synology NAS.
The last-ditch effort would be to bring it to a recovery specialist, but that is REALLY expensive.