[TYPO3-Solr] The page for the given page ID '0' is not marked as root page and can therefore not be used as site root page.

[Peter Kraume]

I get the error message "The page for the given page ID '0' is not 
marked as root page and can therefore not be used as site root page." 
upon editing the page with uid=1 which is directly under the (former) 
globe icon and has pid=0.

Shall I open an issue on Forge? Can this issue be fixed easily?

Cheers
Peter