I have tried to migrate my site to Joomla4, I have done that on a subdomain for testing purpose. This site uses the Royalty template.
Since I have done the migration, all my pages display an error message and I now don´t know what to do. Please see the attachment.
Can you give me advice?
URL of the Joomla4 subdomain: http://joomla4.pils-online.com/