Dear Giorgio,
I had a closer look at your issue and was very puzzled, until I looked
at
https://data.leibnitiana.eu/index.php/Special:Version and realized
you are running an old version of the Wikibase extension that does not
have the "SortedProperties" feature yet. You need to update your
MediaWiki along with a version of the Wikibase extension that fit
together.
Best
Thiemo