Mail: Error by saving attachments under files

Hi,
i have a problem with the mail app when i try to save attachments of a file.
Error message: “Fehler beim Speichern des Anhangs unter Dateien”

Nextcloud version (eg, 12.0.2): 14.0.3.0
Operating system and version (eg, Ubuntu 17.04): Ubuntu 18.04 LTS
Apache or nginx version (eg, Apache 2.4.25): nginx/1.15.6
PHP version (eg, 7.1): 7.2.10

The issue you are facing:

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

Steps to replicate it:

  1. open mail in mail app
  2. go to attachment and click on the folder icon
  3. choose folder in your nextcloud where to store the file

The output of your Nextcloud log in Admin > Logging:

--- 
Error index Error: Function name must be a string

0. /var/www/datastore/lib/private/AppFramework/Http/Dispatcher.php - line 166:OCA\Mail\Controller\MessagesController->saveAttachment(1, "SU5CT1g=", 6552, 2, "/meine OV Dateien")
1. /var/www/datastore/lib/private/AppFramework/Http/Dispatcher.php - line 99:OC\AppFramework\Http\Dispatcher->executeController(OCA\Mail\Con ... {}, "saveAttachment")
2. /var/www/datastore/lib/private/AppFramework/App.php - line 118:OC\AppFramework\Http\Dispatcher->dispatch(OCA\Mail\Con ... {}, "saveAttachment")
3. /var/www/datastore/lib/private/AppFramework/Routing/RouteActionHandler.php - line 47:OC\AppFramework\App::main("OCA\\Mail\\ ... r", "saveAttachment", OC\AppFramew ... {}, { accountId: ... "})
4. OC\AppFramework\Routing\RouteActionHandler->__invoke({ accountId: ... "})
5. /var/www/datastore/lib/private/Route/Router.php - line 297:call_user_func(OC\AppFramew ... {}, { accountId: ... "})
6. /var/www/datastore/lib/base.php - line 987:OC\Route\Router->match("/apps/mail/ ... 2")
7. /var/www/datastore/index.php - line 42:OC::handleRequest() 2018-11-18T22:35:17+0100
Error PHP Undefined variable: pathinfo at /var/www/datastore/apps/mail/lib/Controller/MessagesController.php#299
---

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

$CONFIG = array (
  'instanceid' => 'xxxxxx',
  'passwordsalt' => 'xxxxxxxxx',
  'secret' => 'xxxxxx',
  'trusted_domains' =>
  array (
    0 => 'xxxxx.de',
    1 => '192.xxx.xxx.xxx',
  ),
  'datadirectory' => '/var/datastore_data',
  'dbtype' => 'mysql',
  'version' => '14.0.3.0',
  'overwrite.cli.url' => 'http://xxx.de/datastore',
  'dbname' => 'datastore_db',
  'dbhost' => 'localhost',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'mysql.utf8mb4' => true,
  'dbuser' => 'xxxxxx',
  'dbpassword' => 'xxxxxxxxxx',
  'installed' => true,
  'mail_smtpmode' => 'smtp',
  'mail_smtpsecure' => 'tls',
  'mail_from_address' => 'info',
  'mail_domain' => 'xxxxxxxxxxx',
  'mail_smtpauthtype' => 'LOGIN',
  'mail_smtpauth' => 1,
  'mail_smtphost' => 'smtp.xxxx.de',
  'mail_smtpport' => '587',
  'mail_smtpname' => 'xxxxxxxxxxxx',
  'mail_smtppassword' => 'xxxxxxxxxxx',
  'skeletondirectory' => '',
  'memcache.local' => '\\OC\\Memcache\\APCu',
  'overwriteprotocol' => 'https',
  'logtimezone' => 'Europe/Berlin',
  'maintenance' => false,
  'default_language' => 'de',
);

Hi Chris, did you find an solution, I have this issue too.