Because USB smartcard readers don’t speak a common language. Some are from Gemalto, others from Identiv, HID, or generic vendors. But almost all of them follow the (Chip Card Interface Device) standard — a USB class specification for smartcard readers.

The USBCCID protocol standardizes:

This is often a power management issue with UMDF. The driver might be entering D3 (sleep) and failing to wake.

Users often encounter the following problems with this specific driver: