which Ae version?
Preview will load to RAM as much as it can and then play it.
CC2015 - "Preview" works like this:
Previous versions - "RAM Preview" works like this:
Yeah it's preview i've got.
so any more Questions?
The problem is that it dosen't fully load? it stops at one point so the video playbacks how can i fix that?
Is your question not answered in
my first response? after you read my response and went through the basics I sent you - what exactly is not understood? let me simplify it for you even further - green bar will give you what it can based on your RAM and project specs (how resource intensive it is, how long it is etc.) and most of the time it won't load all the way. That's the way After Effects has always been. If you spend some time going through basic training, you will understand what to expect.