Undefined offset: 1 at /var/www/nextcloud/apps/files_external/lib/Lib/Storage/SMB.php#219

Nextcloud version: 19.0.2
Operating system and version: Ubuntu 20.04
Apache or nginx version: Apache/2.4.41 (Ubuntu)
PHP version: 7.4

The issue you are facing:

Nextcloud log throws below error message. It seems that this is error only occures when the nexcloud client is syncing data from the external smb storage. The external storage is set up with “log-in credentials saved in session” so maybe the session ends before all data is synced and not properly reestablished through the nextcloud client, hence this error. When the external storage is browsed through a webbrowser, this error does not appear.

Is this the first time you’ve seen this error? (Y/N) : Y

Steps to replicate it:

  1. read above

The output of your Nextcloud log in Admin > Logging :

Undefined offset: 1 at /var/www/nextcloud/apps/files_external/lib/Lib/Storage/SMB.php#219

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

<?php
$CONFIG = array (
  'instanceid' => 'blanked',
  'passwordsalt' => 'blanked',
  'secret' => 'blanked',
  'trusted_domains' =>
  array (
    0 => 'blanked',
    1 => 'blanked',
  ),
  'datadirectory' => '/home/data',
  'dbtype' => 'mysql',
  'version' => '19.0.1.1',
  'overwrite.cli.url' => 'https://blanked',
  'htaccess.RewriteBase' => '/',
  'dbname' => 'blanked',
  'dbhost' => 'localhost',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'mysql.utf8mb4' => true,
  'dbuser' => 'blanked',
  'dbpassword' => 'blanked',
  'installed' => true,
  'trusted_proxies' => 'blanked',
  'ldapIgnoreNamingRules' => false,
  'ldapProviderFactory' => 'OCA\\User_LDAP\\LDAPProviderFactory',
  'maintenance' => false,
  'theme' => '',
  'loglevel' => 2,
  'memcache.local' => '\\OC\\Memcache\\APCu',
  'filelocking.enabled' => 'true',
  'memcache.locking' => '\\OC\\Memcache\\Redis',
  'redis' =>
  array (
    'host' => '/var/run/redis/redis-server.sock',
    'port' => 0,
    'timeout' => 1.5,
  ),
  'mail_smtpmode' => 'smtp',
  'mail_smtpsecure' => 'tls',
  'mail_sendmailmode' => 'smtp',
  'mail_from_address' => 'blanked',
  'mail_domain' => 'blanked',
  'mail_smtpauthtype' => 'LOGIN',
  'mail_smtpauth' => 1,
  'mail_smtphost' => 'blanked',
  'mail_smtpport' => '587',
  'mail_smtpname' => 'blanked',
  'mail_smtppassword' => 'blanked',
  'lost_password_link' => 'disabled',
  'skeletondirectory' => '',
  'simpleSignUpLink.shown' => false,
);

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

[Tue Jul 21 00:00:03.967046 2020] [ssl:warn] [pid 1000] AH01909: blanked:443:0 server certificate does NOT include an ID which matches the server name
[Tue Jul 21 00:00:03.967365 2020] [ssl:warn] [pid 1000] AH01909: 127.0.1.1:443:0 server certificate does NOT include an ID which matches the server name
[Tue Jul 21 00:00:03.967492 2020] [mpm_prefork:notice] [pid 1000] AH00163: Apache/2.4.41 (Ubuntu) OpenSSL/1.1.1f configured -- resuming normal operations
[Tue Jul 21 00:00:03.967500 2020] [core:notice] [pid 1000] AH00094: Command line: '/usr/sbin/apache2'
[Tue Jul 21 08:43:27.941131 2020] [access_compat:error] [pid 20584] [client blanked:58788] AH01797: client denied by server configuration: /var/www/nextcloud/config

Please ignore the certificate warnings, there is a reverse proxy in front that handels ssl