Issue with iOS app and folder creation


we have one iPhone which is syncing photos automatically, normally. We set it to “create subfolders”

This worked fine till today. Error messag in iphone app: not allowed to create subfolder.

Error log within nextcloud:
Fatal webdav Sabre\DAV\Exception\MethodNotAllowed: HTTP/1.1 405 The resource you tried to create already exists

/config/www/nextcloud/3rdparty/sabre/dav/lib/DAV/CorePlugin.php - line 590: Sabre\DAV\Server->createCollection('Photos/2017', Object(Sabre\DAV\MkCol))
[internal function] Sabre\DAV\CorePlugin->httpMkcol(Object(Sabre\HTTP\Request), Object(Sabre\HTTP\Response))
/config/www/nextcloud/3rdparty/sabre/event/lib/EventEmitterTrait.php - line 105: call_user_func_array(Array, Array)
/config/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php - line 479: Sabre\Event\EventEmitter->emit('method MKCOL', Array)
/config/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php - line 254: Sabre\DAV\Server->invokeMethod(Object(Sabre\HTTP\Request), Object(Sabre\HTTP\Response))
/config/www/nextcloud/apps/dav/appinfo/v1/webdav.php - line 60: Sabre\DAV\Server->exec()
/config/www/nextcloud/remote.php - line 165: require_once('/config/www/nex...')

iOS is triing to create existing subfolders but can not handle the error …!!!

Nextcloud version (11.0.3):
Operating system and version (Ubuntu Server 16.04):
Apache or nginx version (nginx/1.10.3):
PHP version (php7.0-cli):
Is this the first time you’ve seen this error?:
Can you reliably replicate it? (If so, please outline steps):
The issue you are facing:

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):

The output of your Apache/nginx/system log in /var/log/____:

Remember, this information may be requested if it isn’t supplied; for fastest response please provide as much as you can :heart: Feel free to use a pastebin service, otherwise log files can be indented with 4 spaces on each line to present them in a friendlier way on the forum.