Parent Node does not exist - Operation cancelled

Hi all,
Facing some problems with Nextcloud, been having issues for a while with files and folders being locked but more recently things have come to a standstill with certain folders, I can’t seem to get them to sync at all.

The error shown in the desktop client is “operation cancelled” and the error shown in my logs is:

Fatal	webdav	Sabre\DAV\Exception\Conflict: Parent node does not exist
/var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/CorePlugin.php - line 590: Sabre\DAV\Server->createCollection('files/christov/...', Object(Sabre\DAV\MkCol))
[internal function] Sabre\DAV\CorePlugin->httpMkcol(Object(Sabre\HTTP\Request), Object(Sabre\HTTP\Response))
/var/www/nextcloud/3rdparty/sabre/event/lib/EventEmitterTrait.php - line 105: call_user_func_array(Array, Array)
/var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php - line 479: Sabre\Event\EventEmitter->emit('method MKCOL', Array)
/var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php - line 254: Sabre\DAV\Server->invokeMethod(Object(Sabre\HTTP\Request), Object(Sabre\HTTP\Response))
/var/www/nextcloud/apps/dav/lib/Server.php - line 258: Sabre\DAV\Server->exec()
/var/www/nextcloud/apps/dav/appinfo/v2/remote.php - line 33: OCA\DAV\Server->exec()
/var/www/nextcloud/remote.php - line 162: require_once('/var/www/nextcl...')
{main}

Not really sure where to start here, my knowledge of the system and linux is limited but happy to try solutions! Any help would be appreciated :slight_smile:
Some info below to help

Nextcloud version: 12.0.3
Operating system and version: Ubuntu 16.04.01
Apache or nginx version: Apache 2.4.18 - nginx 1.10.3 (Nginx is used for other services and a reverse proxy, nextcloud is setup outside of this).
PHP version: 7.0.22
Is this the first time you’ve seen this error?: I think so, there are multiple entries in my logs so it may have been happening for some time.

Can you reliably replicate it? (If so, please outline steps): Yes, certain folders simply will not sync when added to the directory structure via a desktop client. This happens on multiple machines.

The issue you are facing: Folders will not sync at all, simply they have a red x next to them in the windows directory structure (main machine being used to access the files).

The output of your Nextcloud log in Admin > Logging: https://goo.gl/5BwdfW

The output of your config.php file in /path/to/nextcloud: https://pastebin.com/XhySbYqM

The output of your Apache/nginx/system log in /var/log/____:
Only allowed to post two links as a new user - had a look at the logs and nothing in there around the time the error hit therefore assuming this isn’t the issue. Happy to post logs if this is required.

bump - any support for this issue?

Hello,

I can confirm similar log messages. Nextcloud tries with MKCOL to create a folder and sees that the parent folder is not there. In my case, I could see in the real log file (text file) that is not abbreviated by …, that the problem is in the folder “_Mit_mir_geteilt”, which was created by the configuration ‘share_folder’ => ‘_Mit_mir_geteilt’.

The parent node (in this case this is a pseudo folder in the database) does not exist.

I have no idea how to solve this.