VLsub unable to download subtitle due to cache folder missing

First reported here: https://github.com/exebetche/vlsub/issues/213

On certain Linux distributions (for me Kubuntu 18.10), VLsub fails to download any subtitle, and instead report the error to the user who is redirected to download it rom the opensubtitles website.

As reported in that link, the problem is that vlc does not create the cache folder, and the workaround is to create it manually

mkdir ~/.cache/vlc

My VLC version is 3.0.4

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information