So I used unrar-free to unrar a file that I wanted to extract. When I gave the command in the CMD it showed me this:
unrar 0.0.1 Copyright (C) 2004 Ben Asselstine, Jeroen Dekkers
Extracting from /home/pi/Downloads/_Getintopc.com_Toon_Boom_Harmony_Premium_17.0.0_Build_14765x64.rar
All OK
Even though it looks like It actually extracted something, it didn't. When I went to my downloads file, I clicked 'Extract here' but It gave me an error saying that it couldn't extract the file.
Could you check if that rar file is maybe empty (or partially downloaded)? For reference, here is what it would have printed if it did find any files in that archive: