Can't synchronize a folder with many sub-folders with Desktop 2.4 and apps

Steps to reproduce

  1. Install oAuth2 app.
  2. Install Desktop client 2.4
    3.Try to synchronize a folder with many sub-folders.

Expected behaviour

Tell us what should happen
Files should synch to local folder.

Actual behaviour

Tell us what happens instead
Desktop app reports an internal server error.

Server configuration

Operating system:
Web server:
mariadb 10.3
PHP version:
ownCloud version: (see ownCloud admin page)
Updated from an older ownCloud or fresh install:
Updated from 10.0.3
Where did you install ownCloud from:
Downloaded tarbal.
Signing status (ownCloud 9.0 and above):


The content of config/config.php:

Too large to post - probably not relevant.

List of activated apps:

  - activity: 2.3.6
  - calendar: 1.5.4
  - comments: 0.3.0
  - configreport: 0.1.1
  - contacts: 1.5.3
  - dav: 0.3.2
  - federatedfilesharing: 0.3.1
  - federation: 0.1.0
  - files: 1.5.1
  - files_clipboard: 0.6.2
  - files_external: 0.7.1
  - files_pdfviewer: 0.8.2
  - files_sharing: 0.10.1
  - files_texteditor: 2.2.1
  - files_trashbin: 0.9.1
  - files_versions: 1.3.0
  - files_videoplayer: 0.9.8
  - firstrunwizard: 1.1
  - gallery: 16.0.2
  - market: 0.2.3
  - notifications: 0.3.2
  - oauth2: 0.2.1
  - ownbackup: 17.7.0
  - provisioning_api: 0.5.0
  - systemtags: 0.3.0
  - tasks: 0.9.3
  - templateeditor: 0.1
  - updatenotification: 0.2.1
  - encryption
  - external
  - user_external

Are you using external storage, if yes which one: local/smb/sftp/...

Are you using encryption: yes/no
Are you using an external user-backend, if yes which one: LDAP/ActiveDirectory/Webdav/...

Client configuration

Operating system:
Windows 10


Web server error log

log is empty

ownCloud log (data/owncloud.log)

{"reqId":"f2633dbb-4526-4d56-9ad9-54d8691e88b3","level":3,"time":"2017-12-27T10:28:41-05:00","remoteAddr":"","user":"handyman","app":"PHP","method":"PROPFIND","url":"\/remote.php\/dav\/files\/handyman\/Saved%20Pictures","message":"PDOStatement::execute(): MySQL server has gone away at \/config\/www\/owncloud\/lib\/composer\/doctrine\/dbal\/lib\/Doctrine\/DBAL\/Driver\/PDOStatement.php#91"}
{"reqId":"f2633dbb-4526-4d56-9ad9-54d8691e88b3","level":3,"time":"2017-12-27T10:28:41-05:00","remoteAddr":"","user":"handyman","app":"PHP","method":"PROPFIND","url":"\/remote.php\/dav\/files\/handyman\/Saved%20Pictures","message":"PDOStatement::execute(): Error reading result set's header at \/config\/www\/owncloud\/lib\/composer\/doctrine\/dbal\/lib\/Doctrine\/DBAL\/Driver\/PDOStatement.php#91"}

I did the following search"MySQL+server+has+gone+away" and found quite a lot of resources like and

It looks like this might be my problem:
kernel: mysqld[25796]: segfault at 0 ip 0000155104128746 sp 00001550d1351508 error 4 in[15510409d000+1c0000]

My ownCloud is in a Docker and mariadb is segfaulting. I removed the folder from ownCloud and I'm re-syncing from a backup. So far it's good, but will take a while. The folder is 21GB.

The problem is back. After 1,013 folders (11,143 files) uploaded, mariadb is segfaulting again. I installed mariadb 10.3 before I realized it was in alpha/beta testing. I updated my system yesterday and noticed an update to 10.3.3 of mariadb. That's when I believe this problem started, so I'm pretty sure it's a mariadb problem.

I just found that this problem occurs with the Android and IOS apps.

I think if the database is crashing / segfaulting you will get issues with most / all operations of ownCloud.

Probably, but so far that's all I've seen. I am trying to roll back to mariadb 10.3.2 without completely messing things up.

I rolled back to mariadb 10.3.2 and the problem is resolved.

Maybe the mariadb project has a bugtracker where you can report such issues? I think this might make sense to avoid that such bugs are released with the next final release.