MTP Thread Error

[tlwright]

This occurred on 5.40 & 5.41. It happens when I plug in my android tablet to transfer books, but doesn't affect the actual transferring of books. Tablet is an Asus Zenbook 7" on Android 7 connecting to Windows 10. The laptop is an HP Envy 17, with an i7 processor from 2016. It's only occurred on 5.4 and 5.41, and didn't happen on earlier versions.

Here's the error info:

calibre, version 5.41.0
ERROR: Unhandled exception: <b>ThreadingViolation</b>:You cannot use the MTP driver from a thread other than the thread in which startup() was called

calibre 5.41 [64bit] embedded-python: True is64bit: True
Windows-10-10.0.19041 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.19041')
Python 3.8.5
Windows: ('10', '10.0.19041', '', 'Multiprocessor Free')
Interface language: None
Successfully initialized third party plugins: Gather KFX-ZIP (from KFX Input) (1, 48, 0) && DeDRM (10, 0, 2) && Package KFX (from KFX Input) (1, 48, 0) && Action Chains (1, 16, 3) && Amazon.com Multiple Countries (1, 0, 0) && Annotations (1, 17, 0) && Audit Log (1, 0, 16) && Barnes & Noble (1, 2, 16) && Calibre Power Search Plugin (2, 1, 2) && CalibreCV (0, 0, 6) && CalibreSpy (1, 0, 84) && Category Tags (0, 2, 3) && Check Books (0, 1, 0) && Consolidate All Library Metadata (2, 0, 40) && Count Pages (1, 11, 2) && Drop Search Results (1, 0, 11) && Embed Comic Metadata (1, 6, 1) && EpubCheck (0, 2, 4) && EpubMerge (2, 13, 0) && EpubSplit (3, 3, 0) && Extract ISBN (1, 5, 0) && FanFicFare (4, 11, 0) && Fantastic Fiction (1, 5, 1) && Fantastic Fiction Adults (1, 2, 0) && Find Duplicates (1, 9, 4) && Generate Cover (2, 1, 0) && Goodreads (1, 5, 3) && Goodreads More Tags (1, 2, 1) && Goodreads Sync (1, 15, 1) && Goodreads_Rating (3, 1, 0) && ISFDB3 (1, 0, 2) && Import List (1, 8, 2) && Job Spy (1, 0, 190) && KFX metadata reader (from KFX Input) (1, 48, 0) && KFX Input (1, 48, 0) && Set KFX metadata (from KFX Output) (1, 61, 0) && KFX Output (1, 61, 0) && KOReader Sync (0, 2, 7) && KePub Input (3, 4, 3) && KePub Metadata Reader (3, 4, 3) && KePub Metadata Writer (3, 4, 3) && KePub Output (3, 5, 3) && Kindle Collections (1, 7, 29) && Kindle hi-res covers (0, 5, 0) && Kobo Books (1, 9, 0) && Kobo Utilities (2, 15, 1) && Last Modified (0, 8, 2) && Library Codes (1, 0, 50) && LibraryThing Match (0, 2, 0) && Manage Series (1, 3, 0) && Modify ePub (1, 7, 0) && MultiColumnSearch (1, 0, 87) && Obok DeDRM (10, 0, 0) && Overdrive Link (2, 51, 0) && Quality Check (1, 12, 0) && Reading List (1, 8, 0) && Save Composite Custom Columns (1, 1, 1) && Save Virtual Libraries To Column GUI (2, 3, 0) && Skoob Books (1, 5, 4) && SmartEject (2, 4, 0) && Smashwords Metadata (1, 0, 2) && Standard Ebooks (1, 0, 0) && User Category (1, 5, 5) && WordDumb (3, 19, 0) && Overdrive Link Metadata Source (2, 51, 0)
Traceback (most recent call last):
File "calibre_plugins.annotations.action", line 1043, in on_device_connection_changed
File "calibre_plugins.annotations.action", line 1261, in rebuild_menus
File "calibre_plugins.annotations.action", line 368, in get_connected_device_primary_name
File "calibre\devices\mtp\driver.py", line 196, in get_device_information
File "calibre\devices\mtp\windows\driver.py", line 34, in check_thread
calibre.devices.mtp.windows.driver.ThreadingViolat ion: You cannot use the MTP driver from a thread other than the thread in which startup() was called

[kovidgoyal]

That's caused by the annotations plugin you should report it there.

[tlwright]

Gotcha, will do.

[davidfor]

Sorry, I didn't look at this properly and thought it was accessing under Linux. Rereading it now, it is under Windows and I can reproduce it. I had not seen it before as I had my phone on the ignore list.

I have posted a beta in the Annotations plugin thread. That fixes the problem under Windows and should be OK elsewhere.

[tlwright]

I'll give it a try! It did it with my phone as well as the tablet.

[Trimbuk2]

Hello everyone, I'm new in the community, I get this error

calibre, version 6.9.0
ERROR: Error: Error in the communication with the device

C:\rc:336:Failed to EnumObjects() of folder from device:[hr=0x802a0006 wCode=0] Cannot determine requested value: o62D6

Traceback (most recent call last):
File "calibregui2device.py", line 88, in run.
File "calibregui2device.py", line 540, in _books
File "calibre\devices\mtp\driver.py", line 219, in books
File "calibre\devices\mtpp\driver.py", line 191, in get_driveinfo
File "calibre\devices\mtpp\windows\driver.py", line 271, in filesystem_cache
wpd.WPDError: C:\rc\src\src\calibre\devices\mtpp\windows\content _enumeration.cpp:336:Failed to EnumObjects() of folder from device:[hr=0x802a0006 wCode=0] Cannot determine requested value: o62D6


I don't have the Annotations add-on, until a moment ago Calibre didn't give me that error and I was transferring books to my p30 without conflicts, I thought the error was because I hadn't updated the Calibre version and I did it, but I still get that same message.

[kovidgoyal]

That is an error listing the files in the device storage. This has been known to happen with some
devices when they contain SD cards. If you remove the SD card, you should be fine. You can try reformatting the card
or using a different card as well.

[Trimbuk2]

Hi, I really appreciate your answer, I have already formatted the MicroSD, and indeed... I can add books without getting any error.