Plex won't connect locally on Mac Mini since installing plugin

I installed the WebTools then trakt.tv plugin using this:

https://github.com/trakt/Plex-Trakt-Scrobbler/wiki/Installation - macOS (Terminal)

Every since, I cannot open Plex running on my Mac Mini. localhost:32400 and 127.0.0.1:32400 don't work. I've tried signing out and back in, no luck, says server is Unavailable.