Computer no longer shows up on apple tv

Yesterday I was able to watch a show in my iTunes library on my computer through my apple tv. Today I can not. The computer app no longer appears on the apple tv home screen. I did not touch or change anything. Both computer and apple tv signed into same account and on same internet( both ethernet connected). Both have home shareing turned on. I am able to air play. I just have no access to my iTunes video library through the apple tv any more. Help!