Hi,
Thank you for your help. As you might guess, I'm not a professional and dealing with the website is always a bit try and error...
I re-installed the raw version of Helix ultimate and the same error came up (after more than 5 min). This is the report:
[https://rgzv-delbrueck.de/images/Screenshot.jpg]
I was thinking of redoing the modifications in the template from scratch - but if the raw template doesn't work either, this is no point.
By the way: I get the same situation in another version in a subdomain with Joomla 5 and a different database.
Re-Edit:
I saw in line two that the template still refers to my modified template even if it is no longer standard. In my Joomly 5 subdomain I completely deleted the modified template and reinstalled helix ultimate. This fixed the error. (http://2024.rgzv-delbrueck.de/verein.html)
But now I sadly have to redo my template.