Hi, thanks for the hint, I tested it, all settings were OK, but I added the server again. Unfortunately the problem still occurs. Please find attached the information from Zentral.
Einige Module meldeten ein Fehler beim Sichern der Änderungen. Weitere Informationen finden Sie in den Logs in /var/log/zentyal/
The following modules failed while saving their changes, their state is unknown: dns The following modules failed while saving their changes, their state is unknown: dns at The following modules failed while saving their changes, their state is unknown: dns at /usr/share/perl5/EBox/GlobalImpl.pm line 727 EBox::GlobalImpl::saveAllModules('EBox::GlobalImpl=HASH(0x556cc602d2b8)', 'progress', 'EBox::ProgressIndicator=HASH(0x556cc1e0d698)') called at /usr/share/perl5/EBox/Global.pm line 95 EBox::Global::AUTOLOAD('EBox::Global=HASH(0x556cc5eee040)', 'progress', 'EBox::ProgressIndicator=HASH(0x556cc1e0d698)') called at /usr/share/zentyal/global-action line 32 eval {...} at /usr/share/zentyal/global-action line 30