.. since the current plex server version: 0.9.11.4.739-a4e710f
the agent doesn´t find anything.
only a spinning wheel comes up, if you search by themoviedb agent !
EDIT: see this thread: https://forums.plex.tv/topic/128761-agents-not-working-09114739-a4e710f/
it looks like that´s not only a problem the themoviedb agent.. freebase and thetvdb also has the same problems with doing a manual search !