Bitte mal folgendes probieren
www.joomlaplates.de/forum/joomla-4-templ...nology-template.html

Hallo,
leider hat das nicht geholfen, Fehler ist noch da.

Gruß Norbert

Hallo ,
von dem RSEvent! Support wurde mir das als mögliche Fehlerursache geschrieben:

This is most likely caused by your template missing specific jdoc declarations, in this case used to display system type messages and when your event validation takes place.

You'll need to contact your template developers directly on this matter:

docs.joomla.org/Jdoc_statements

More precisely, they need to include:
<jdoc:include type="message" />

Afterwards, try adding a new event one more time from the frontend area.
Regards!

Hello, you can add the Joomla System message like this

Hello,
This is present, other messages are also displayed. Only not with the RSEvent!Pro.

Sorry then I have no sultion now!
we cannot guarantee the templates will function with all 3rd party components as there is currently no certification process for such components