Are you seeing "???" in filenames? Inside the UI or in your ftp client?
If inside the Skylark UI, could you please share screenshots?
If in ftp client - that is caused by your ftp client (or your OS) not handling unicode well. Filezilla seems to work well. See if that fixes the issue.
There are some articles that show a "404" when you view them in the News app - those are due to the source website sending a 404 inside of a page instead of reporting a 404 http error. I am trying to filter those out, and most are caught, but some do get thru. But these should not have "??" in their filenames inside the Skylark UI (Whats New app or Filemanager or News app in the middle column).