Question: Why does the host report an error message "USB device not recognized" when I connect some Full-Speed (FS) or Low-Speed (LS) devices to the downstream port of the HX3 hub?
The High-Speed section of an USB 3.0 hub supports USB version 2.1. Some older operating systems (Windows 7, Windows XP or Vista) do not properly handle split transfers when working with USB 2.1-capable hubs, affecting the functionality of the FS and LS devices connected with the hub. This issue is addressed in subsequent service packs of Windows operating systems.
If your FS/LS device connected to HX3’s downstream port doesn’t work or the host reports “USB device not recognized”, we recommend that you update the host operating systems to the latest service packs to resolve this issue. This issue is not observed in Windows-7 service pack-1 (and later), Windows XP service pack 2 (and later), Windows 8.0, and Windows 8.1.