nextcloud
[Bug]: Versions 3.16, 3.17: Windows 11 Explorer and Nextcloud crash on right-click
⚠️ Before submitting, please verify the following: ⚠️
- [x] This is a bug, not a question or a configuration issue.
- [x] This issue is not already reported on Github (I've searched it).
- [x] Nextcloud Server and Desktop Client are up to date. See Server Maintenance and Release Schedule and Desktop Releases for supported versions.
- [x] I agree to follow Nextcloud's Code of Conduct
Bug description
From versions 3.16 onwards trying to right-click on a folder or file in Windows Explorer (Windows 11) crashes both explorer and the Nextcloud desktop client. Nothing resolves until opening Task Manager to restart Explorer and Nextcloud. I have had to roll back to 3.15 to resolve the problem.
Steps to reproduce
- Right click on a file or folder
- Explorer and Nextcloud will crash
- That's it
Expected behavior
Windows Explorer and the Nextcloud desktop client should not crash when right-clicking on a file or folder.
Which files are affected by this bug
I don't know how to identify that
Operating system
Windows
Which version of the operating system you are running.
Windows 11
Package
Official Windows MSI
Nextcloud Server version
30.0.14
Nextcloud Desktop Client version
3.16, 3.17
Is this bug present after an update or on a fresh install?
Updated to a major version (ex. 3.3.6 to 3.4.0)
Are you using the Nextcloud Server Encryption module?
Encryption is Disabled
Are you using an external user-backend?
- [x] Default internal user-backend
- [ ] LDAP/ Active Directory
- [ ] SSO - SAML
- [ ] Other
Nextcloud Server logs
Additional info
I have had the same issue since 3.15.0 (last version where nextcloud works). Any time I update, nextcloud starts with sync paused, even if there is no account linked. No interaction with the icon in the system tray works (e.g. left/ right click on the icon does nothing and I cannot open the settings) and any right click in explorer causes an explorer crash.
The most recent client, 3.17.2 has even more unusual behaviour, such as duplicating my accounts in the windows navigation pane after the first attempt at upgrade. Simply reinstalling v3.15.0 usually works normally, though as of the most recent version, it removed my accounts forcing me to re-link my account. I have tried fresh installs, unlinking and linking accounts, deleting all sync data all with no result.
Using Windows 10 enterprise, nextcloud server version 31.0.9 (selfhosted). The service works fine on my other devices (windows 10 and 11).
It also does not appear to be creating any logs. In my log folder %appdata%\Nextcloud\Logs the only logs are from a single date in March of this year and nothing since. I can see no setting within the desktop client (version 3.15.0) to enable logging and cannot open the app on any more recent version to check if this needs to be enabled. Is there some other place I can enable or review logs?
could you check if you have a log file called %TMP%/Nextcloud-crash.log or %TEMP%/Nextcloud-crash.log ?
could you check if you have a log file called
%TMP%/Nextcloud-crash.logor%TEMP%/Nextcloud-crash.log?
Yes! I'll update to the latest version this evening and copy across the crash logs. Thanks
@mgallien I've just updated to 4.0.1 and nextcloud crashes/ quits with the crash log below. If I reopen nextcloud, it starts with sync paused but the tray icon is non-responsive and there is nothing new in the crash log apart from what is copied below. Looks like the database is locked but no idea why that would be? Works fine on my other two computers. Thanks
2025-11-19 22:05:14:123 [ debug nextcloud.sync.database C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\common\syncjournaldb.cpp:3219 ] [ OCC::SyncJournalDb::commitInternal ]: Transaction commit "checkConnect End" 2025-11-19 22:05:14:127 [ info nextcloud.gui.folder.manager C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\gui\folderman.cpp:1306 ]: Adding folder to Folder Map OCC::Folder(0x1e325442570) "1" 2025-11-19 22:05:14:127 [ info nextcloud.gui.folder.manager C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\gui\folderman.cpp:737 ]: Schedule folder "1" to sync! 2025-11-19 22:05:14:127 [ info nextcloud.gui.folder.manager C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\gui\folderman.cpp:750 ]: Folder is not ready to sync, not scheduled! 2025-11-19 22:05:14:127 [ info nextcloud.sync.database C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\common\syncjournaldb.cpp:85 ]: Detected filesystem "NTFS" for "D:/Nextcloud/.sync_1da5e928e72e.db" 2025-11-19 22:05:14:127 [ debug nextcloud.gui.folder C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\gui\folder.cpp:184 ] [ OCC::Folder::checkLocalPath ]: Checked local path ok 2025-11-19 22:05:14:129 [ info nextcloud.sync.configfile C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\libsync\configfile.cpp:1302 ]: Adding user defined ignore list to csync: "C:/Users/Malek/AppData/Roaming/Nextcloud/sync-exclude.lst" 2025-11-19 22:05:14:129 [ debug nextcloud.gui.folder C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\gui\folder.cpp:528 ] [ OCC::Folder::startVfs ]: Display name for VFS folder will be: "Nextcloud - 1004789.xyz - malek" 2025-11-19 22:05:14:129 [ debug nextcloud.sync.filesystem C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\common\filesystembase.cpp:819 ] [ OCC::FileSystem::setAclPermission ]: allocated a new DACL object of size 124 2025-11-19 22:05:14:130 [ debug nextcloud.sync.filesystem C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\common\filesystembase.cpp:819 ] [ OCC::FileSystem::setAclPermission ]: allocated a new DACL object of size 124 2025-11-19 22:05:14:130 [ debug nextcloud.sync.filesystem C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\common\filesystembase.cpp:819 ] [ OCC::FileSystem::setAclPermission ]: allocated a new DACL object of size 124 2025-11-19 22:05:14:130 [ debug nextcloud.sync.filesystem C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\common\filesystembase.cpp:819 ] [ OCC::FileSystem::setAclPermission ]: allocated a new DACL object of size 212 2025-11-19 22:05:14:130 [ debug nextcloud.sync.filesystem C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\common\filesystembase.cpp:819 ] [ OCC::FileSystem::setAclPermission ]: allocated a new DACL object of size 212 2025-11-19 22:07:02:097 [ warning nextcloud.sync.database.sql C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\common\ownsql.cpp:253 ]: Sqlite prepare statement error: "database is locked" in "PRAGMA quick_check;" 2025-11-19 22:07:02:097 [ warning nextcloud.sync.database.sql C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\common\ownsql.cpp:85 ]: Error preparing quick_check on database 2025-11-19 22:07:02:097 [ critical nextcloud.sync.database.sql C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\common\ownsql.cpp:138 ]: Consistency check failed, removing broken db "D:/Nextcloud/.sync_1da5e928e72e.db" 2025-11-19 22:07:02:097 [ info nextcloud.sync.database C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\common\syncjournaldb.cpp:335 ]: sqlite3 version "3.42.0" 2025-11-19 22:07:02:097 [ info nextcloud.sync.database C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\common\syncjournaldb.cpp:347 ]: sqlite3 locking_mode= "exclusive" 2025-11-19 22:08:49:559 [ warning nextcloud.sync.database.sql C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\common\ownsql.cpp:253 ]: Sqlite prepare statement error: "database is locked" in "PRAGMA journal_mode=WAL;" 2025-11-19 22:08:49:559 [ fatal default C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\common\ownsql.cpp:254 ]: ENFORCE: "allow_failure" in file C:\Users\User\AppData\Local\Temp\windows-34592\client-building\desktop\src\common\ownsql.cpp, line 254 with message: SQLITE Prepare error
I've just noticed that it has now created 3 nextcloud entries in the windows explorer preview pane. All other issues the same.
The problem becomes severe when a large number of files need to be synced with the server. Under heavy workload, the Nextcloud client appears to hang and creates a bottleneck that affects the entire system.
It seems that the Windows Explorer integration (right-click context menu extension) might be contributing to the problem. When the sync load is high, Explorer becomes unresponsive on right-clicks and eventually crashes. In some cases, even the Nextcloud client itself crashes.
This suggests that the client may not be managing threads efficiently during large sync operations, causing the shell extension to block Explorer.
