Hello, Stephan,
We are pleased to inform you that we have successfully imported the demo content onto your website – https://prnt.sc/fvDJcoAz9LAB To view the updated content, please clear your browser’s cache and visit the site.
Please do not enable 3rd party plugins before demo content import, because it looks like some of them, caused the issue for you and once we disable such plugins, all is fine.
Warm regards,
The 8Theme Team