Error accessing files from external storage SMB/CIFS

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Nextcloud version : 17.03
Operating system and version : Ubuntu 16.04
Apache or nginx version : 2.4.39
PHP version : 7.3.7

The issue you are facing:

Proxy error 502 when trying to access file mounted on an SMB/CIFS external storage. Not all files will fail, but most do. I am not running a reverse proxy.

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

Steps to replicate it:

  1. Try to access a file on an external storage

The output of your Nextcloud log in Admin > Logging:

I don't know where this log is

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

$CONFIG = array (
  'instanceid' => 'ocoyvtv3rxwi',
  'passwordsalt' => 'XXXXXX',
  'secret' => 'XXXXXX',
  'trusted_domains' =>
  array (
    0 => '',
    1 => 'XXXXX.local',
    2 => 'XXXXX',
    3 => 'XXXXX',
  'memcache.local' => '\\OC\\Memcache\\APCu',
  'datadirectory' => '/var/nextcloud/data',
  'overwrite.cli.url' => '',
  'dbtype' => 'mysql',
  'version' => '',
  'dbname' => 'nextcloud',
  'dbhost' => 'localhost',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'dbuser' => 'nextcloud',
  'dbpassword' => 'XXXX',
  'logtimezone' => 'UTC',
  'installed' => true,
  'ldapIgnoreNamingRules' => false,
  'ldapProviderFactory' => '\\OCA\\User_LDAP\\LDAPProviderFactory',
  'ldapUserCleanupInterval' => 20,
  'mail_smtpmode' => 'smtp',
  'maintenance' => false,
  'loglevel' => 2,
  'mail_from_address' => 'cloud',
  'mail_domain' => 'XXXXX',
  'mail_smtphost' => 'XXXXXX',
  'mail_smtpport' => '25',
  'session_keepalive' => false,
  'remember_login_cookie_lifetime' => 1296000,
  'session_lifetime' => 3600,
  'theme' => '',
  'mysql.utf8mb4' => true,
  '' => 'stable',
  'updater.secret' => 'XXXXXX',

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

Nothing interesting

Exact error when trying to download:

Proxy Error

The proxy server received an invalid response from an upstream server.
The proxy server could not handle the request *[GET /nextcloud/index.php/apps/files/ajax/download.php]

Reason: Error reading from remote server

1 Like

Hi jgooden,

did u resolve ur issue? We receive the same error in different Nextcloud versions based on UCS. I opened a thread in their support community but didn’t receive an answer, too.

In our environment it’s possible to upload files at any size, but in case of downloading, just very small files (>1mb) work.