Hi, So I have a lot of hard drives. As the macs have problems having these internally, I have keep them externally. I have 5 different USB docks, of different makes and models. 3 of them are a bit older (C, D, E), the other 2 (A, B) just purchased last week. The hard drives I have are of several different sizes. Here is the problem: Whenever I insert one of the hard drives formatted in any of the 3 older docks into any of the newer docks, I get a “The disk you inserted was not readable by this computer” error. If I insert it into the older docks, it works without a hitch. When I insert one of the drives formatted by the newer docks into any of the older docks, I get another “The disk you inserted was not readable by this computer”. If I insert a drive formatted in new dock A into new dock B, it still works properly. If I insert a drive formatted in any old dock (Say, docks C, D, E) into any other old dock which was not used to format it, I get another “The disk you inserted was not readable by this computer” error. This happens on any drive I have which is 3TB or larger. All other drives <= 2TB work properly in all docks. Brands are either WD Green or HGST. The old docks are two different Plugable models, and an Anker model. The new ones are a Cable Matters model and an Orico transparent one. Does anyone have any experience with this?