Cached Frames?

[Chris Voelz]

It means you hit preview and play before the machine had a chance to cache any frames. The green bar above the comp timeline indicates how much has cached. Just hit preview and wait for some frames to cache before trying to play them back. I accidentally do this all the time.

[Chip Hess]

Thanks!
I did a search on the Adobe forum, and found this

Preferences > Memory, and make sure “Reduce Cache size when system is low on memory” is NOT checked.
I found this fixed it!