Last modified: 2013-01-23 01:04:18 UTC
Not sure since when this feature is broken but when the |captionproperty= is using a page type entity recursiveTagParse() would only produce a normal href instead of a wikitext (see [1]). [1] http://semantic-mediawiki.org/wiki/Demo:Gallery/Standard_gallery_using_parameter_captionproperty
https://gerrit.wikimedia.org/r/#/c/44849/3