I wanted to find all Semantic MediaWiki properties on wikitech to fix a bad [[Special:Ask]] query on it, so I visited https://wikitech.wikimedia.org/wiki/Special:Properties
That request returns a header with
HTTP/1.0 500 Internal Server Error Content-Length: 0
Firefox and chromium display a blank page. The same happens with Special:WantedProperties and Special:UnusedProperties. But other SMW special pages work OK, such as Special:Types.
Expected results: these special pages should work, they're in the Special pages list. In addition the blank page suggests wikitech's error page may be misconfigured along with Semantic MediaWiki.