Why does my external harddrive not work when attached to this USB3 Hub? I own a Macbook Pro 15" Mid 2015 which supports USB 3.0 and bought a Western Digital 2TB external USB3 harddrive and a USB 3.0 Hub from Anker with external power supply.

When I plug-in the harddrive directly to the Macbook everything is fine.

When I plug-in an Apple Thunderbolt display to the Macbook's Thunderbolt2 port and then plug-in the harddrive to the USB2.0 port of the display, it works too but it's very slow due to USB2.0 limitation.

So I bought the Anker USB hub and thought it would be alright as long as it has an external power supply. But when I plug-in the hub to the USB3 port of the Macbook and then attach the harddrive to the hub it doesn't work. The drive gets mounted and unmounted automatically in OSX all the time.

Basically like this:

Macbook USB3 ------  USB3 Harddrive                                  OK!
Macbook TB2  ------   Display USB2   ------ USB3 Harddrive           OK!
Macbook USB3 ------     Hub USB3     ------ USB3 Harddrive      Not working :-(


What's going on?
I finally found the solution. After contacting Anker as well as WD I found out that both, the Hub as well as the harddisk were fine. The cause for the problem was a low quality usb extension cable that was attached to my Macbook. After removing that and directly attaching the hub to the Macbook, everything works fine.