The license is not recognized if it is a non-German version of the license.
Examples:
https://commons.wikimedia.org/wiki/File:14-08-10-wikimania-gruppenfoto-01.jpg (Creative Commons Attribution-Share Alike 3.0 Austria)
https://commons.wikimedia.org/wiki/File:Serena_Williams_at_the_Australian_Open_2015.jpg (Creative Commons Attribution 2.0 Generic)
From:
https://github.com/wmde/Lizenzverweisgenerator/issues/61 and
https://github.com/wmde/Lizenzverweisgenerator/issues/60