Calibre was communicating with Android phone, now won't

SteveG23 · 04-16-2026, 05:57 PM

Using Windows 11 Pro, Calibre 9.7. I had cleaned off the library from my Android (Samsung A54, Android 14) phone to make sure Calibre 9.7 was managing it properly. I got the library on the desktop PC and then on the phone back to a fresh start and used Calibre to load a few dozen of my existing epubs. Then I took a bit of a break and found that the last batch of files I tried to copy hadn't gone through. I tried again, and now I consistently get the dreaded "error communicating with device." In the Details, I get:

C:\r\src\src\calibre\devices\mtp\windows\content_e numeration.cpp:855:Cannot write to file:[hr=0x80004005 wCode=0 name=unknown] Unspecified error

Calibre does read the library of files already copied to the device; just won't let me add new ones.
I have tried:
> rebooting the computer and the Android device;
> deleting driveinfo.calibre and metadata.calibre
> changing to a different cable and USB port
> making sure I can read the device folder from my computer in File Explorer before restarting Calibre

What have I not tried?

kovidgoyal · 04-16-2026, 10:45 PM

Thats an error trying to write a file to the device, if rebooting it and computer doesnt work then your remaining options are reset the device or use one of the wireless transfer methods.

u100009 · 05-22-2026, 11:41 PM

I had a similar fate... I switched to a new Android phone (from old Redmi Note 10 to a 14 Pro).. All my ePub books (about 260) where transferred to the new phone by the wireless Xioami "Mi Mover" and are now sitting on the main storage of my new phone. After re-installing KOreader on the new phone too, I hoped that Calibre would recognize all my existing books on the phone without having to resend them all wirelessly, as they would show up as duplicates.. (I tried a few ones and that's what happened).
Then I tried to use the "Android Driver" to connected by USB, pointing the plugin to my folder in Windows Explorer, but that resulted in an error that nothing was found, so I disconnected the phone and restarted Calibre. But after the next Calibre connect from the device over Wifi, now all the books I had transferred (a dozen or so) are not there anymore .. gone!..

Is there any ways to tell Calibre to force scanning all the eBooks from KOreader on the phone, so the books would show up again in the 'Device' list ?

I've tried everything for a few hours now and couldn't find any useful hint on any of the usual Calibre or KOreader forums..

TiA for any suggestions that would avoid me to delete all my eBooks on the phone and re-transfer them wirelessly from Calibre.

kovidgoyal · 05-23-2026, 02:58 AM

You can control what folders are scanned by right clicking on the device icon in calibre and choosing configure this device.

u100009 · 05-27-2026, 04:16 PM

Thank you... but unless I'm missing something, there is no place in the 'configure this device' screen to specify which folder to scan for books ? Do I need an extra plugin to perform this action ?

kovidgoyal · 05-27-2026, 09:56 PM

The setting is called Save template and th ehelp text for it says it controls the filename and location of sent books.

Jinz · 05-30-2026, 05:54 PM

I just solved exactly this kind of problem by taking the micro-sd card out of the reader and running Windows checkdisk on it. There are apparently corruptions that the Android system won't fix correctly and then the whole books directory doesn't make it through the MTP/USB interface anymore, as well as denying writes.

u100009 · Yesterday, 04:36 PM

Quote:

Originally Posted by kovidgoyal

The setting is called Save template and th ehelp text for it says it controls the filename and location of sent books.

The "Save Template" field has only this as my default path for folders & Books creation: {series}/{authors:sublist(0,1,&)}-{title}

There is nothing there that can tell me to scan my root location from KOreader to scan for existing books.. This is not an SD card.. this the main memory of my new phone.

kovidgoyal · Yesterday, 08:48 PM

If you want to change the set of folders scanned for books on an mtp device there is a button for it right there in the config dialog as well.

u100009 · Yesterday, 09:54 PM

Thanks..
To some point that worked.. it was able to find over 400 files, but not all of them are .epub files.. most of it is junk from other folder from the root of the phone.. Once I switch back to Wireless connection, it only shows the 20 books I transfered from Calibre.. even the one I sent while connected MTP was put in the root of the Books folder..
it's like it can't refresh the database with all the existing books.. so the whole point is useless about connecting thru MTP ..

04-16-2026, 05:57 PM	#1
SteveG23 Junior Member Posts: 5 Karma: 10 Join Date: Apr 2012 Device: iPaq - MS Reader	Calibre was communicating with Android phone, now won't Using Windows 11 Pro, Calibre 9.7. I had cleaned off the library from my Android (Samsung A54, Android 14) phone to make sure Calibre 9.7 was managing it properly. I got the library on the desktop PC and then on the phone back to a fresh start and used Calibre to load a few dozen of my existing epubs. Then I took a bit of a break and found that the last batch of files I tried to copy hadn't gone through. I tried again, and now I consistently get the dreaded "error communicating with device." In the Details, I get: C:\r\src\src\calibre\devices\mtp\windows\content_e numeration.cpp:855:Cannot write to file:[hr=0x80004005 wCode=0 name=unknown] Unspecified error Calibre does read the library of files already copied to the device; just won't let me add new ones. I have tried: > rebooting the computer and the Android device; > deleting driveinfo.calibre and metadata.calibre > changing to a different cable and USB port > making sure I can read the device folder from my computer in File Explorer before restarting Calibre What have I not tried?

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04-16-2026, 10:45 PM	#2
kovidgoyal creator of calibre Posts: 46,274 Karma: 29630860 Join Date: Oct 2006 Location: Mumbai, India Device: Various	Thats an error trying to write a file to the device, if rebooting it and computer doesnt work then your remaining options are reset the device or use one of the wireless transfer methods.

05-22-2026, 11:41 PM	#3
u100009 Junior Member Posts: 7 Karma: 10 Join Date: Aug 2025 Location: QC, CA Device: Kobo Libra 2	I had a similar fate... I switched to a new Android phone (from old Redmi Note 10 to a 14 Pro).. All my ePub books (about 260) where transferred to the new phone by the wireless Xioami "Mi Mover" and are now sitting on the main storage of my new phone. After re-installing KOreader on the new phone too, I hoped that Calibre would recognize all my existing books on the phone without having to resend them all wirelessly, as they would show up as duplicates.. (I tried a few ones and that's what happened). Then I tried to use the "Android Driver" to connected by USB, pointing the plugin to my folder in Windows Explorer, but that resulted in an error that nothing was found, so I disconnected the phone and restarted Calibre. But after the next Calibre connect from the device over Wifi, now all the books I had transferred (a dozen or so) are not there anymore .. gone!.. Is there any ways to tell Calibre to force scanning all the eBooks from KOreader on the phone, so the books would show up again in the 'Device' list ? I've tried everything for a few hours now and couldn't find any useful hint on any of the usual Calibre or KOreader forums.. TiA for any suggestions that would avoid me to delete all my eBooks on the phone and re-transfer them wirelessly from Calibre.

05-23-2026, 02:58 AM	#4
kovidgoyal creator of calibre Posts: 46,274 Karma: 29630860 Join Date: Oct 2006 Location: Mumbai, India Device: Various	You can control what folders are scanned by right clicking on the device icon in calibre and choosing configure this device.

05-27-2026, 04:16 PM	#5
u100009 Junior Member Posts: 7 Karma: 10 Join Date: Aug 2025 Location: QC, CA Device: Kobo Libra 2	Thank you... but unless I'm missing something, there is no place in the 'configure this device' screen to specify which folder to scan for books ? Do I need an extra plugin to perform this action ?

05-27-2026, 09:56 PM	#6
kovidgoyal creator of calibre Posts: 46,274 Karma: 29630860 Join Date: Oct 2006 Location: Mumbai, India Device: Various	The setting is called Save template and th ehelp text for it says it controls the filename and location of sent books.

05-30-2026, 05:54 PM	#7
Jinz Connoisseur Posts: 51 Karma: 42052 Join Date: Jan 2014 Device: Likebook Mars, Imcosys V6l, Trekstor Pyrus	I just solved exactly this kind of problem by taking the micro-sd card out of the reader and running Windows checkdisk on it. There are apparently corruptions that the Android system won't fix correctly and then the whole books directory doesn't make it through the MTP/USB interface anymore, as well as denying writes.

Yesterday, 08:48 PM	#9
kovidgoyal creator of calibre Posts: 46,274 Karma: 29630860 Join Date: Oct 2006 Location: Mumbai, India Device: Various	If you want to change the set of folders scanned for books on an mtp device there is a button for it right there in the config dialog as well.

Yesterday, 09:54 PM	#10
u100009 Junior Member Posts: 7 Karma: 10 Join Date: Aug 2025 Location: QC, CA Device: Kobo Libra 2	Thanks.. To some point that worked.. it was able to find over 400 files, but not all of them are .epub files.. most of it is junk from other folder from the root of the phone.. Once I switch back to Wireless connection, it only shows the 20 books I transfered from Calibre.. even the one I sent while connected MTP was put in the root of the Books folder.. it's like it can't refresh the database with all the existing books.. so the whole point is useless about connecting thru MTP ..

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