I've been playing around with OctoberCMS for a while now, and when I changed the language of the backend to Polish, it's not loading lang.pl.js (/modules/system/assets/js/lang/lang.pl.js?v437). Other languages work just fine (and the files are loading properly). The file does exist obviously, and has the same permissions as the other files. When I change the name of the file I can load it in browser just fine.

Does anyone know what might be the cause? My best guess is server blocking it since the file loads fine in October locally.