Unable to write Operation Cancelled

Could really use some help on this one guys!

Nextcloud version (11.0.2):
Operating system and version (Ubuntu 16.04):
Apache version (Apache 2.4.18):
PHP version (eg, 7.0.15):
Is this the first time you’ve seen this error?:

Yes, but I can no longer add/remove/sync files and folders to nextcloud so it persists

Can you reliably replicate it? (If so, please outline steps):

Yes, try adding a new file to sync group, operation fails. I am also unable to upload via the web UI getting “Connection to host lost”. Occasionally will work with small files ~1MB

The issue you are facing:

Unable to sync files and folders any longer

The output of your Nextcloud log in Admin > Logging:

2017-04-19T09:42:31-0400

Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-19T09:13:34-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 7074328 got 49152 2017-04-19T09:13:31-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 356549 got 49152 2017-04-19T09:13:29-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 0 2017-04-19T09:12:36-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 7074328 got 0 2017-04-19T09:12:30-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 356549 got 0 2017-04-19T09:12:29-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-19T09:12:03-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-19T09:11:57-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 7074328 got 49152 2017-04-19T09:11:57-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-19T08:57:34-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 7074328 got 49152 2017-04-19T08:57:29-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-19T08:57:29-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-19T06:57:04-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-19T06:56:59-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 7074328 got 49152 2017-04-19T06:56:59-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-19T04:56:33-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-19T04:56:29-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 7074328 got 49152 2017-04-19T04:56:29-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 0 2017-04-19T04:51:48-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-19T02:56:03-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-19T02:55:58-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 7074328 got 49152 2017-04-19T02:55:58-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-19T02:55:03-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-19T02:54:58-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 7074328 got 49152 2017-04-19T02:54:58-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-19T02:54:34-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-19T02:54:34-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-19T02:54:28-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 7074328 got 16384 2017-04-19T02:49:28-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-19T00:54:03-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 7074328 got 49152 2017-04-19T00:53:58-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-19T00:53:58-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-18T22:53:33-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 7074328 got 49152 2017-04-18T22:53:28-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-18T22:53:28-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-18T20:53:04-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 7074328 got 49152 2017-04-18T20:52:57-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-18T20:52:57-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-18T20:52:33-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-18T20:52:28-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 7074328 got 49152 2017-04-18T20:52:28-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-18T18:52:02-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-18T18:51:58-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 7074328 got 49152 2017-04-18T18:51:58-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-18T16:51:34-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 7074328 got 49152 2017-04-18T16:51:28-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-18T16:51:28-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-18T16:51:04-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 7074328 got 49152 2017-04-18T16:50:58-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-18T16:50:58-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-18T14:50:13-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-18T14:50:12-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 7074328 got 49152 2017-04-18T14:50:07-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-18T14:49:41-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-18T14:49:37-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 7074328 got 49152 2017-04-18T14:49:37-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 0 2017-04-18T14:45:07-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 16384 2017-04-18T14:45:07-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-18T13:39:47-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-18T13:39:33-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-18T13:39:33-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-18T13:39:28-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-18T13:38:22-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-18T13:38:08-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-18T13:38:08-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-18T13:38:03-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-18T13:37:46-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-18T13:37:33-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-18T13:37:33-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-18T13:37:28-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 92158 got 49152 2017-04-18T11:37:16-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-18T11:37:02-0400
Fatal webdav Sabre\DAV\Exception\BadRequest: HTTP/1.1 400 expected filesize 10000000 got 49152 2017-04-18T11:37:02-0400

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

<?php $CONFIG = array ( 'instanceid' => 'EDITED', 'passwordsalt' => 'EDITED', 'secret' => 'EDITED', 'trusted_domains' => array ( 0 => '10.9.0.5', 1 => 'nEDITED', ), 'datadirectory' => '/nextcloud/data', 'overwrite.cli.url' => 'https://EDITED', 'dbtype' => 'mysql', 'version' => '11.0.2.7', 'dbname' => 'nextcloud', 'dbhost' => 'localhost', 'dbport' => '', 'dbtableprefix' => 'oc_', 'dbuser' => 'EDITED', 'dbpassword' => 'EDITED', 'logtimezone' => 'UTC', 'installed' => true, 'memcache.local' => '\\OC\\Memcache\\APCu', 'memcache.locking' => '\\OC\\Memcache\\Redis', 'filelocking.enabled' => 'true', 'redis' => array ( 'host' => '/var/run/redis/redis.sock', 'port' => 0, 'timeout' => 0.0, ), 'loglevel' => 2, 'mail_from_address' => 'EDITED', 'mail_smtpmode' => 'php', 'mail_domain' => 'EDITED', 'maintenance' => false, 'theme' => '', 'updater.release.channel' => 'stable', 'htaccess.RewriteBase' => '/', ); The output of your Apache/nginx/system log in `/var/log/____`: cat /var/log/apache2/error.log [Wed Apr 19 06:25:02.010372 2017] [ssl:warn] [pid 2635] AH01906: cloud.domain.com:443:0 server certificate is a CA certificate (BasicConstraints: CA == TRUE !?) [Wed Apr 19 06:25:02.010443 2017] [ssl:warn] [pid 2635] AH01909: cloud.domain.com:443:0 server certificate does NOT include an ID which matches the server name [Wed Apr 19 06:25:02.010676 2017] [mpm_prefork:notice] [pid 2635] AH00163: Apache/2.4.18 (Ubuntu) OpenSSL/1.0.2g configured -- resuming normal operations [Wed Apr 19 06:25:02.010690 2017] [core:notice] [pid 2635] AH00094: Command line: '/usr/sbin/apache2' ---

Dear Mr. gabe_beaver,
I am facing the same problem with my nextcloud,
There shows the message …
Unable to write
Operation Cancelled

I am really appreciate, if somebody help.

I’m also getting this on a windows system now. On my GNU/Linux system, I got another error, which I’ve described in another thread, so basically, I can’t use it, cause no platform works.

Dear Sir …
Can anyone help about this error…?

I’m a single-person user and this started happening to me the next day after doing a restore for some files contained in an entirely different folder structure.

I wonder if this could be caused by some stale / incorrect values being stored somewhere?

Update: Deleting and re-creating the folder tree did not resolve it. This is quite a serious bug.

If you are using apache2 as webserver: https://github.com/nextcloud/server/issues/15095