Plugin localization doesn’t work

Hi,
I pressed the link on the UM notification saying “Download the translation files and start using the plugin in your language now” – for Polish language. After that there’s another notification saying “Your translation files have been updated successfully.” – but it doesn’t work and there are not *-pl_PL* files in /ultimate-member/languages/ folder. And there is no file repository to do that manually, although the plugin page says Polish is available. How to make this work?
Thx.