After upgrade to 8.2.1.4 error when syncing big fil

I recently upgraded to 8.2.7 After that I constantly got an error when syncing my files with the server. I relates to a .PST file that is over 2Gb. Before, V8.2.1.4, it synced without problems
The desktop client says:
.....xxx.pst-chunking-8617289978-186-185 - server replied: Service Unavailable

The log on the server says:
Exception: {"Message":"HTTP\/1.1 423 \"Backup\/Documenten\/Outlook-bestanden\/johan.dewit@chello.nl.pst-chunking-861728978-186-185\" is locked","Exception":"OC\Connector\Sabre\Exception\FileLocked","Code":0,"Trace":"#0 \/home\/deb48734\/domains\/familiedewit.net\/public_html\/cloud\/3rdparty\/sabre\/dav\/lib\/DAV\/Server.php(1053): OC\Connector\Sabre\Directory->createFile('johan.dewit@che...', Resource id #113)\n#1 \/home\/deb48734\/domains\/familiedewit.net\/public_html\/cloud\/3rdparty\/sabre\/dav\/lib\/DAV\/CorePlugin.php(513): Sabre\DAV\Server->createFile('Backup\/Document...', Resource id #113, NULL)\n#2 [internal function]: Sabre\DAV\CorePlugin->httpPut(Object(Sabre\HTTP\Request), Object(Sabre\HTTP\Response))\n#3 \/home\/deb48734\/domains\/familiedewit.net\/public_html\/cloud\/3rdparty\/sabre\/event\/lib\/EventEmitterTrait.php(105): call_user_func_array(Array, Array)\n#4 \/home\/deb48734\/domains\/familiedewit.net\/public_html\/cloud\/3rdparty\/sabre\/dav\/lib\/DAV\/Server.php(469): Sabre\Event\EventEmitter->emit('method:PUT', Array)\n#5 \/home\/deb48734\/domains\/familiedewit.net\/public_html\/cloud\/3rdparty\/sabre\/dav\/lib\/DAV\/Server.php(254): Sabre\DAV\Server->invokeMethod(Object(Sabre\HTTP\Request), Object(Sabre\HTTP\Response))\n#6 \/home\/deb48734\/domains\/familiedewit.net\/public_html\/cloud\/apps\/files\/appinfo\/remote.php(56): Sabre\DAV\Server->exec()\n#7 \/home\/deb48734\/domains\/familiedewit.net\/public_html\/cloud\/remote.php(137): require_once('\/home\/deb48734\/...')\n#8 {main}","File":"\/home\/deb48734\/domains\/familiedewit.net\/public_html\/cloud\/lib\/private\/connector\/sabre\/directory.php","Line":121}

What can I do? (I'm not an php expert)

regards,
Johan

Hi,

the following FAQ contains everything known about the "file is locked" message in your logfile:

I'll give it a try
thanks