Error communicating with device, new Kindle

Hello,

I got a new Kindle Fire 7 yesterday and am trying to upload my ebooks to the device. When I try to send the files to the device, I get an "error communicating with device" popup.

C:\r\src\src\calibre\devices\mtp\windows\content_e numeration.cpp:336:Failed to EnumObjects() of folder from device:[hr=0x80042009 wCode=7689] IDispatch error #7689: o10

Traceback (most recent call last):
File "calibre\gui2\device.py", line 88, in run
File "calibre\gui2\device.py", line 540, in _books
File "calibre\devices\mtp\driver.py", line 219, in books
File "calibre\devices\mtp\driver.py", line 191, in get_driveinfo
File "calibre\devices\mtp\windows\driver.py", line 271, in filesystem_cache
wpd.WPDError: C:\r\src\src\calibre\devices\mtp\windows\content_e numeration.cpp:336:Failed to EnumObjects() of folder from device:[hr=0x80042009 wCode=7689] IDispatch error #7689: o10

Any help would be greatly appreciated.