When an image is used as a link (using the link= attribute) and the link uses the interwiki syntax (e.g. [[Image:Foo.jpg|20px|link=n:Foobar]]), the Wikipedia Android app tries to show the destination as a local article (in the popup), failing with an error message saying the page does not exist.

See e.g. the main page of cswiki which uses Template:Viz Wikizprávy in the “In the News” (“Aktuality”) section to render small Wikinews logos next to those news having corresponding Wikinews articles. When you click the image, an error appears instead of going to the Wikinews page (in an external browser, as usual for interwiki links in the app).

Reported at cswiki, reproduced in 2.7.50350-beta-2021-04-02.