After Editing Blocks on the Home Page
http://d287451.iomundo.com/index.php/de-de/
via SP Page Builder, the home page now renders a broken header with the warning with Warning "JUser: :_load: Fehler beim Laden des Benutzers mit der ID: 746".
https://imgur.com/a/r6cY1p4
We never had a user with that ID 746. The header with main menu still works on other pages like
http://d287451.iomundo.com/index.php/de-de/spenden
What can be the reason? I never changed the header.