This broke VLC launching for me, though i think the regression is actually from the previous release:

https://github.com/webtorrent/webtorrent-desktop/issues/1807

In-case anyone has the same issue... downgrading alone is not sufficient to fix, as the issue seems to be with the configuration stored in .config/WebTorrent Once you remove this and install 0.21 or less VLC will launch again.