Now I can't download

I logged in, but when I go to a particular book in my library and click on 'download epub', it just redirects to me to a page completely filled with illegible text

*annoyed*
ETA: I tried now with another book and got the error message "Cannot download. The content is not supported on the Reader".

I already have lots of books from kobobooks there (transferred via the Reader software on my pc). I don't get it.