Plugin not working, reporting unable to register delete funtions

[AlphaDE]

I just installed the plugin on a fresh ISPConfig3 3.3.0p3 multiserver installation and granted the ispconfig user the necessary ALTER right.

Nevertheless, no config options came up, neither on the master nor on the email server.

Instead I find (when enabling debug logging on the master)

02.01.2026-16:01 - DEBUG [plugins.inc:98] - Unable to register function 'mail_user_delete' from plugin 'nextcloud_plugin' for event 'ma
il_user_delete'
02.01.2026-16:01 - DEBUG [plugins.inc:98] - Unable to register function 'mail_domain_delete' from plugin 'nextcloud_plugin' for event '
mail_domain_delete'

in the ispconfig.log logfile.

What's wrong?

ISPConfig 3.30.p3, nginx, php 8.3, Ubuntu 24.04 LTS