In this edit (among others), I used the automated reference interpreter to fill the citation template: https://nl.wikipedia.org/w/index.php?title=Miro_Cerar&diff=prev&oldid=49432423
Most of the included references in Slovenian did not have the language recognized, except this one:
<ref name=":1">{{Citeer web|url=http://www.student.si/preberi-si/aktualno/intervju-prof-dr-miro-cerar.html|titel=INTERVJU - prof. dr. Miro Cerar|bezochtdatum=2017-07-10|auteur=Študent|taal=si-SI}}</ref>(where the parameter 'taal' is the language parameter). The language code used is si, which is sinhalese - quite uncomparable a language with even a different script. Seems like the language code is somehow mixed up? The language code should have been sl (if insisting to add country, sl-si ).