Support intro
Sorry to hear you’re facing problems 
help.nextcloud.com is for home/non-enterprise users. If you’re running a business, paid support can be accessed via portal.nextcloud.com where we can ensure your business keeps running smoothly.
In order to help you as quickly as possible, before clicking Create Topic please provide as much of the below as you can. Feel free to use a pastebin service for logs, otherwise either indent short log examples with four spaces:
example
Or for longer, use three backticks above and below the code snippet:
longer
example
here
Some or all of the below information will be requested if it isn’t supplied; for fastest response please provide as much as you can 
Nextcloud version (eg, 20.0.5): 26.0.1
Operating system and version (eg, Ubuntu 20.04): Truenas Freebsd
Apache or nginx version (eg, Apache 2.4.25): apache24
PHP version (eg, 7.4): 8.1
The issue you are facing:
After upgrading from nextcloud 25 to 26, one of my 2 local storages is not visible anymore.
Weird thing is they both on the same path and they both have green mark in external storage stating that everything is ok.
Both storages have been stup and working for few years.
Also, I get that message in overview:
There are some warnings regarding your setup.
This instance is missing some recommended PHP modules. For improved performance and better compatibility it is highly recommended to install them.
sysvsem
smb-client is installed
Is this the first time you’ve seen this error? (Y/N): Y
Steps to replicate it:
- share local storage in nextcloud
- upgrade from 25 to 26.
The output of your Nextcloud log in Admin > Logging:
Error files_external Icewind\SMB\Exception\DependencyException: No valid backend available, ensure smbclient is in the path or php-smbclient is installed
Warning no app in context OCP\Files\StorageNotAvailableException: No valid backend available, ensure smbclient is in the path or php-smbclient is installed
The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):
<?php
$CONFIG = array (
'instanceid' => 'oc9b2buzq16j',
'passwordsalt' => '',
'secret' => '',
'trusted_domains' =>
array (
0 => '',
1 => '',
2 => '',
),
'datadirectory' => '/mnt/data',
'dbtype' => 'mysql',
'version' => '26.0.1.1',
'overwrite.cli.url' => '',
'dbname' => 'nextcloud',
'dbhost' => 'localhost:/tmp/mysql.sock',
'dbport' => '',
'dbtableprefix' => 'oc_',
'mysql.utf8mb4' => true,
'dbuser' => '',
'dbpassword' => '',
'installed' => true,
'default_phone_region' => 'FR',
'updater.release.channel' => 'stable',
'default_locale' => 'fr_FR',
'default_language' => 'fr',
'activity_expire_days' => 14,
'auth.bruteforce.protection.enabled' => 'false',
'skeletondirectory' => 'false',
'blacklisted_files' =>
array (
0 => '.htaccess',
1 => 'Thumbs.db',
2 => 'thumbs.db',
),
'cron_log' => true,
'enable_previews' => true,
'enabledPreviewProviders' =>
array (
0 => 'OC\\Preview\\PNG',
1 => 'OC\\Preview\\JPEG',
2 => 'OC\\Preview\\GIF',
3 => 'OC\\Preview\\BMP',
4 => 'OC\\Preview\\XBitmap',
5 => 'OC\\Preview\\Movie',
6 => 'OC\\Preview\\PDF',
7 => 'OC\\Preview\\MP3',
8 => 'OC\\Preview\\TXT',
9 => 'OC\\Preview\\MarkDown',
),
'filesystem_check_changes' => 0,
'filelocking.enabled' => 'true',
'redis' =>
array (
'host' => '/var/run/redis/redis.sock',
'port' => 0,
),
'trusted_proxies' =>
array (
0 => '',
),
'maintenance' => false,
'memcache.local' => '\\OC\\Memcache\\APCu',
'mail_from_address' => '',
'mail_smtpmode' => 'smtp',
'mail_smtpsecure' => 'tls',
'mail_sendmailmode' => 'smtp',
'mail_domain' => 'gmail.com',
'mail_smtpauthtype' => 'LOGIN',
'mail_smtpauth' => 1,
'mail_smtphost' => 'smtp.orange.fr',
'mail_smtpport' => '587',
'mail_smtpname' => '',
'mail_smtppassword' => '',
'loglevel' => 2,
'theme' => '',
'app_install_overwrite' =>
array (
0 => 'files_trackdownloads',
),
);