Failed to enumerate disk

Last week I tried to connect a 2Tb and a 1Tb disk via a usb3 dock to my MyCloud. The disk was not visible, so I logged in with ssh and looked into the /var/log/messages file. There i saw that the disk was seen on the mycloud, but also the message “failed to enumerate disk”. This happened with both disks.
I formatted the disks first with extfat and after that on NTFS. But nothing changed.
On my windows pc both disks were perfectly usable via the usb3 dock on both extfat and ntfs.
What can be the problem?

Some of us have experienced similar issues that have been discussed in a couple of threads (see below). In my case I had two external USB hard drives (one from Toshiba and one generic docking station) that wouldn’t be properly mounted by the My Cloud v4.x firmware. The solution for the Thoshiba drive was to delete the partition(s), then reparation the drive then reformat for NTFS. I used a Windows 7 PC to do the reformatting/repartitioning. I talk about it in the following post:

Other threads where this issue is discussed.