I had the same issue today (not used in a while). Had to ssh and type 'emby4.start' to get it to run.
Before that I uninstalling and re-installed, but issue continues. Annoyingly I now need to setup emby again!
Does anyone know how to fix this? Thanks.
EDIT: After about 10 mins emby shut down, so am having to play moves outside of emby for now.