[unpaws]

I also have a newly delivered A6X2, but mine is still not recognized by Calibre I get the same error as described above:

calibre, version 7.7.0
FEHLER: Fehler: Fehler beim Kommunizieren mit dem Gerät

C:\r\src\src\calibre\devices\mtp\windows\content_enumeration.cpp:710:Cannot write to file:[hr=0x80004005 wCode=0] Unbekannter Fehler

Traceback (most recent call last):
  File "calibre\gui2\device.py", line 104, in run
  File "calibre\gui2\device.py", line 558, in _books
  File "calibre\devices\mtp\driver.py", line 230, in books
  File "calibre\devices\mtp\driver.py", line 203, in get_driveinfo
  File "calibre\devices\mtp\driver.py", line 193, in _update_drive_info
  File "calibre\devices\mtp\driver.py", line 163, in put_calibre_file
  File "calibre\devices\mtp\windows\driver.py", line 35, in check_thread
  File "calibre\devices\mtp\windows\driver.py", line 447, in put_file
wpd.WPDError: C:\r\src\src\calibre\devices\mtp\windows\content_enumeration.cpp:710:Cannot write to file:[hr=0x80004005 wCode=0] Unbekannter Fehler

The debug command shows a different device identifier in my case:

MTP device: \\?\usb#vid_2207&pid_0017&mi_00

It would be great to add this one as well