[Bug]: invalid `__NC_ROOT__` directory present in the file provider root

[nilsding]

⚠️ Before submitting, please verify the following: ⚠️

• This is a bug, not a question or a configuration issue.
• This issue is not already reported on Github (I've searched it).
• Nextcloud Server and Desktop Client are up to date. See Server Maintenance and Release Schedule and Desktop Releases for supported versions.
• I agree to follow Nextcloud's Code of Conduct

Bug description

On 4.0.0-rc1, enabling VFS for an account will create an unexpected directory named __NC_ROOT__ in the file provider root. Attempting to access this directory will fail as it's not present on the server:

From what I can tell an update of the NextcloudKit dependency might have introduced that.

Steps to reproduce

• Set up a new account with VFS enabled

Expected behavior

This directory should not be present at all -- the file provider extension must only display items from the server or created locally.

Which files are affected by this bug

n/a

Operating system

macOS

Which version of the operating system you are running.

macOS 15.3.1

Package

Official macOS Virtual files 12+ universal pkg

Nextcloud Server version

32

Nextcloud Desktop Client version

4.0.0-rc1

Is this bug present after an update or on a fresh install?

Updated to a major version (ex. 3.16.3 to 3.17.0)

Are you using the Nextcloud Server Encryption module?

Encryption is Disabled

Are you using an external user-backend?

• Default internal user-backend
• LDAP/ Active Directory
• SSO - SAML
• Other

Nextcloud Server logs

not relevant

Additional info

File provider logs:

Enumerator setup

{"category":"Enumerator","date":"2025-10-03_13-26-36","details":{},"level":"debug","message":"Providing enumerator for a system defined container:\nNSFileProviderRootContainerItemIdentifier","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"Enumerator","date":"2025-10-03_13-26-36","details":{},"level":"info","message":"Set up enumerator for user: admin http:\/\/nextcloud.local\nwith serverUrl: http:\/\/nextcloud.local\/remote.php\/dav\/files\/admin","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"Enumerator","date":"2025-10-03_13-26-36","details":{},"level":"debug","message":"Received enumerate items request for enumerator with user:\nadmin http:\/\/nextcloud.local\nwith serverUrl: http:\/\/nextcloud.local\/remote.php\/dav\/files\/admin","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"Enumerator","date":"2025-10-03_13-26-36","details":{},"level":"debug","message":"Enumerating page: FPPageSortedByName\u0000\n    for user: admin http:\/\/nextcloud.local\n    with serverUrl: http:\/\/nextcloud.local\/remote.php\/dav\/files\/admin","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"Enumerator","date":"2025-10-03_13-26-36","details":{"url":"http:\/\/nextcloud.local\/remote.php\/dav\/files\/admin"},"level":"debug","message":"Starting to read server URL.","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"Enumerator","date":"2025-10-03_13-26-36","details":{},"level":"debug","message":"Starting async conversion of NKFiles for serverUrl: http:\/\/nextcloud.local\/remote.php\/dav\/files\/admin for user: admin http:\/\/nextcloud.local","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"FilesDatabaseManager","date":"2025-10-03_13-26-36","details":{"metadata":{"account":"admin http:\/\/nextcloud.local","contentType":"application\/pdf","creationDate":777974303,"date":777974303,"deleted":false,"directory":false,"downloaded":false,"eTag":"ccf29ac0afe62e742445fe0ff8a0550e","keepDownloaded":false,"lock":false,"lockOwner":null,"lockTimeOut":"nil","name":"Nextcloud_Server_Administration_Manual.pdf","ocId":"00000003oc7xqbonfcnw","permissions":"RGDNVW","serverUrl":"http:\/\/nextcloud.local\/remote.php\/dav\/files\/admin","size":8822513,"syncTime":781183596.442563,"trashbinFileName":"","uploaded":true,"visitedDirectory":false}},"level":"debug","message":"Created new item metadata during update.","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"FilesDatabaseManager","date":"2025-10-03_13-26-36","details":{"metadata":{"account":"admin http:\/\/nextcloud.local","contentType":"httpd\/unix-directory","creationDate":777974303,"date":777974303,"deleted":false,"directory":true,"downloaded":false,"eTag":"68aeba9fecd69","keepDownloaded":false,"lock":false,"lockOwner":null,"lockTimeOut":"nil","name":"Templates","ocId":"00000013oc7xqbonfcnw","permissions":"RGDNVCK","serverUrl":"http:\/\/nextcloud.local\/remote.php\/dav\/files\/admin","size":0,"syncTime":781183596.442597,"trashbinFileName":"","uploaded":true,"visitedDirectory":false}},"level":"debug","message":"Created new item metadata during update.","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"FilesDatabaseManager","date":"2025-10-03_13-26-36","details":{"metadata":{"account":"admin http:\/\/nextcloud.local","contentType":"httpd\/unix-directory","creationDate":779794026,"date":779794026,"deleted":false,"directory":true,"downloaded":false,"eTag":"68ca7eea56c58","keepDownloaded":false,"lock":false,"lockOwner":null,"lockTimeOut":"nil","name":"__NC_ROOT__","ocId":"00000002oc7xqbonfcnw","permissions":"GDNVCK","serverUrl":"http:\/\/nextcloud.local\/remote.php\/dav\/files\/admin","size":20575003,"syncTime":781183596.442614,"trashbinFileName":"","uploaded":true,"visitedDirectory":false}},"level":"debug","message":"Created new item metadata during update.","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"FilesDatabaseManager","date":"2025-10-03_13-26-36","details":{"metadata":{"account":"admin http:\/\/nextcloud.local","contentType":"application\/octet-stream","creationDate":779792520,"date":779792520,"deleted":false,"directory":false,"downloaded":false,"eTag":"7bd8cf36887405e7405bba2d92f0b833","keepDownloaded":false,"lock":false,"lockOwner":null,"lockTimeOut":"nil","name":"test","ocId":"00000150oc7xqbonfcnw","permissions":"RGDNVW","serverUrl":"http:\/\/nextcloud.local\/remote.php\/dav\/files\/admin","size":0,"syncTime":781183596.44263,"trashbinFileName":"","uploaded":true,"visitedDirectory":false}},"level":"debug","message":"Created new item metadata during update.","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"FilesDatabaseManager","date":"2025-10-03_13-26-36","details":{"metadata":{"account":"admin http:\/\/nextcloud.local","contentType":"httpd\/unix-directory","creationDate":779794026,"date":779794026,"deleted":false,"directory":true,"downloaded":false,"eTag":"68ca7eea55b7c","keepDownloaded":false,"lock":false,"lockOwner":null,"lockTimeOut":"nil","name":"untitled folder","ocId":"00000152oc7xqbonfcnw","permissions":"RGDNVCK","serverUrl":"http:\/\/nextcloud.local\/remote.php\/dav\/files\/admin","size":0,"syncTime":781183596.442643,"trashbinFileName":"","uploaded":true,"visitedDirectory":false}},"level":"debug","message":"Created new item metadata during update.","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"FilesDatabaseManager","date":"2025-10-03_13-26-36","details":{},"level":"info","message":"Depth 1 read target is new: 00000004oc7xqbonfcnw","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"Enumerator","date":"2025-10-03_13-26-36","details":{},"level":"info","message":"Finished reading page:\n    FPPageSortedByName\u0000\n    serverUrl: http:\/\/nextcloud.local\/remote.php\/dav\/files\/admin\n    for user: admin http:\/\/nextcloud.local.\n    Processed 6 metadatas","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"toFileProviderItems","date":"2025-10-03_13-26-36","details":{"name":"Media","ocId":"00000004oc7xqbonfcnw"},"level":"debug","message":"Will enumerate item.","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"toFileProviderItems","date":"2025-10-03_13-26-36","details":{"name":"Templates","ocId":"00000013oc7xqbonfcnw"},"level":"debug","message":"Will enumerate item.","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"toFileProviderItems","date":"2025-10-03_13-26-36","details":{"name":"__NC_ROOT__","ocId":"00000002oc7xqbonfcnw"},"level":"debug","message":"Will enumerate item.","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"toFileProviderItems","date":"2025-10-03_13-26-36","details":{"name":"test","ocId":"00000150oc7xqbonfcnw"},"level":"debug","message":"Will enumerate item.","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"toFileProviderItems","date":"2025-10-03_13-26-36","details":{"name":"Nextcloud_Server_Administration_Manual.pdf","ocId":"00000003oc7xqbonfcnw"},"level":"debug","message":"Will enumerate item.","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"toFileProviderItems","date":"2025-10-03_13-26-36","details":{"name":"untitled folder","ocId":"00000152oc7xqbonfcnw"},"level":"debug","message":"Will enumerate item.","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"Enumerator","date":"2025-10-03_13-26-36","details":{},"level":"info","message":"Did enumerate 6 items","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"Enumerator","date":"2025-10-03_13-26-36","details":{},"level":"info","message":"Next page is nil: true","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"Enumerator","date":"2025-10-03_13-26-36","details":{},"level":"debug","message":"Enumerator is being invalidated for item with identifier:\nNSFileProviderRootContainerItemIdentifier","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"MaterialisedEnumerationObserver","date":"2025-10-03_13-26-36","details":{},"level":"debug","message":"Handling enumerated materialised items.","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"MaterialisedEnumerationObserver","date":"2025-10-03_13-26-36","details":{"ocId":"NSFileProviderRootContainerItemIdentifier"},"level":"error","message":"No metadata for NSFileProviderRootContainerItemIdentifier found","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"MaterialisedEnumerationObserver","date":"2025-10-03_13-26-36","details":{"name":"Media","ocId":"00000004oc7xqbonfcnw"},"level":"info","message":"Updating materialisation state for item to DATALESS with id 00000004oc7xqbonfcnw with filename Media.","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"FilesDatabaseManager","date":"2025-10-03_13-26-36","details":{"metadata":{"account":"admin http:\/\/nextcloud.local","contentType":"httpd\/unix-directory","creationDate":777974303,"date":777974303,"deleted":false,"directory":true,"downloaded":false,"eTag":"68aeba9fe7aec","keepDownloaded":false,"lock":false,"lockOwner":null,"lockTimeOut":"nil","name":"Media","ocId":"00000004oc7xqbonfcnw","permissions":"RGDNVCK","serverUrl":"http:\/\/nextcloud.local\/remote.php\/dav\/files\/admin","size":11752490,"syncTime":781183596.442327,"trashbinFileName":"","uploaded":true,"visitedDirectory":false}},"level":"debug","message":"Added item metadata.","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"Enumerator","date":"2025-10-03_13-26-36","details":{},"level":"debug","message":"Providing enumerator for a system defined container:\nNSFileProviderTrashContainerItemIdentifier","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}

Attempt to open __NC_ROOT__

{"category":"Enumerator","date":"2025-10-03_13-26-45","details":{},"level":"debug","message":"Providing enumerator for item with identifier:\n00000002oc7xqbonfcnw","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"Enumerator","date":"2025-10-03_13-26-45","details":{},"level":"info","message":"Set up enumerator for user: admin http:\/\/nextcloud.local\nwith serverUrl: http:\/\/nextcloud.local\/remote.php\/dav\/files\/admin\/__NC_ROOT__","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"Enumerator","date":"2025-10-03_13-26-45","details":{},"level":"debug","message":"Received enumerate items request for enumerator with user:\nadmin http:\/\/nextcloud.local\nwith serverUrl: http:\/\/nextcloud.local\/remote.php\/dav\/files\/admin\/__NC_ROOT__","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"Enumerator","date":"2025-10-03_13-26-45","details":{},"level":"debug","message":"Enumerating page: FPPageSortedByName\u0000\n    for user: admin http:\/\/nextcloud.local\n    with serverUrl: http:\/\/nextcloud.local\/remote.php\/dav\/files\/admin\/__NC_ROOT__","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"Enumerator","date":"2025-10-03_13-26-45","details":{"url":"http:\/\/nextcloud.local\/remote.php\/dav\/files\/admin\/__NC_ROOT__"},"level":"debug","message":"Starting to read server URL.","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"Enumerator","date":"2025-10-03_13-26-45","details":{"error":{"code":1,"domain":"NextcloudKit.NKError","localizedDescription":"The operation couldn’t be completed. (NextcloudKit.NKError error 1.)"},"url":"http:\/\/nextcloud.local\/remote.php\/dav\/files\/admin\/__NC_ROOT__"},"level":"error","message":"Read of URL did fail.","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"Enumerator","date":"2025-10-03_13-26-45","details":{},"level":"error","message":"Finishing enumeration for page:\n    FPPageSortedByName\u0000\n    for: admin http:\/\/nextcloud.local\n    with serverUrl: http:\/\/nextcloud.local\/remote.php\/dav\/files\/admin\/__NC_ROOT__ \n    with error File with name \/\/__NC_ROOT__ could not be located","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"Enumerator","date":"2025-10-03_13-26-45","details":{},"level":"debug","message":"Enumerator is being invalidated for item with identifier:\n00000002oc7xqbonfcnw","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}
{"category":"Enumerator","date":"2025-10-03_13-26-45","details":{},"level":"debug","message":"Enumerator is being invalidated for item with identifier:\nNSFileProviderRootContainerItemIdentifier","subsystem":"com.nextcloud.desktopclient.FileProviderExt"}

[AndyXheli]

Same issue on MacOS 26.0.1

[nilsding]

NCFPK dependency updated in #8838