Very bad translation

This plugin has a very, very bad translation which makes it unusable.
The first thing – the links to monthly view of calendar are translated – but the correct link which works is for polish “miesiac”, but all buttons in the calendar generate link and redirect to “miesi?c” (with a diacritic letter), which means that no link inside the calendar actually works – changing to daily view, to list view, jumping to next event, etc. -> Why are the links even translated, and why are the same link translated to two different words and breaking the file?
Second thing – The first text that user sees when seeing the calendar: “There were no results found for this view. Jump to the next upcoming event(s).” is nowhere in the translations file and there is no way to change it. -> Why one of the most important strings is not translatable?