Problem: Nextcloud Complains About "No valid backend available"

Problem:

In Nextcloud you get an error like this and accessing Samba shares within Nextcloud does not work.

"Es ist ein Fehler mit folgender Meldung aufgetreten:Icewind\SMB\Exception\DependencyException: No valid backend available, ensure smbclient is in the path or php-smbclient is installed. Do you want to review mount point config in admin settings page?"

Environment

Nextcloud app version: 19.0.3-0

Solution

Nextloud realized the smbclient offers poor performance and decided to switch to PHP smbclient. But enabling this in PHP was missed.
This is a known issue on Nextcloud and will be addressed. As a workaround enable the PHP package manually or install smbclient.

Option 1 (recommended)

univention-app shell nextcloud 
echo 'extension=smbclient.so' >> /etc/php/7.4/apache2/conf.d/60-nextcloud.ini
echo 'extension=smbclient.so' >> /etc/php/7.4/cli/conf.d/60-nextcloud.ini
exit
univention-app restart nextcloud

Option 2

univention-app shell nextcloud apt install smbclient

Option 3

univention-app shell nextcloud
apt upgrade
apt install smbclient libsmbclient-dev