Why do USB timeouts happen: getting device descriptor at addr 5 failed, USB_ERR_TIMEOUT ?

[Yuri]

I have a USB Hantek PC-oscilloscope.

Several seconds after the PulseView program begins to upload firmware 
into it, the device disconnects:

ugen8.5: <vendor 0x04b4 product 0x6022> at usbus8
ugen8.5: <vendor 0x04b4 product 0x6022> at usbus8 (disconnected)
usbd_setup_device_desc: getting device descriptor at addr 5 failed, 
USB_ERR_TIMEOUT
usbd_setup_device_desc: getting device descriptor at addr 5 failed, 
USB_ERR_TIMEOUT
usbd_setup_device_desc: getting device descriptor at addr 5 failed, 
USB_ERR_TIMEOUT
usbd_setup_device_desc: getting device descriptor at addr 5 failed, 
USB_ERR_TIMEOUT
usbd_setup_device_desc: getting device descriptor at addr 5 failed, 
USB_ERR_TIMEOUT
ugen8.5: <Unknown > at usbus8 (disconnected)


I don't believe that the device is broken, it is brand new.

Why would the device access, no mater what it is, cause the timeout and 
disconnect?


Yuri