Syntax like "[[File:Foo.jpg]]" normally displays a thumbnail of the file
(and apparently does something weird when a file is not an image).
To link to the file's page, use "[[:File:Foo.jpg]]" (note the colon
':'
at the beginning). See also examples at
<https://www.mediawiki.org/wiki/Help:Links#Internal_links>.
--
Bartosz Dziewoński