Tell us about your machine -- how much memory do you have? It appears it isn't much.
It is an HP Omen, it has 8 gigs of Ram and 1tb of memory storage which I haven't even used half of.
You must have a boatload of other applications open. AE will preview using all the RAM available to it. It appears you're getting a aecond or two at best.
Also: purge your caches and try the preview again.
I tried purging and it did not help, and i only have my browser and After Effects open.
That's not the world's most detailed screen grab, but i think I see your comp window is at Full resolution. The actual size of the comp viewer isn't anywhere near 100% Do yourself a favor: set the viewer size to 25%, the resolution to Quarter and try again.
My machine has 16 gigs and I wouldn't DREAM of getting any more than a 15-second chunk of a 1280x720 comp to preview.
You just have to learn how AE previews, I guess. You've probably noticed it doesn't work like a video editing application. You'll discover more.
I cannot make out much of the details in your screenshot. Try just using PrintScreen and then pasting in the reply field on this forum so the text is not so distorted. Make sure your composition is selected in the Project Panel and that the layer giving you problems has all modified properties revealed. The only thing I can really make out is that you have applied Motion tile and something else to the selected layer. You could be working with a comp and effect settings that are eating up all your ram.
I always have my Comp Panel resolution set to Auto. This is the most efficient way to work. This will match your resolution to the magnification ratio for the composition panel and give you longer previews when working at reduced magnification factors.
If that does not help then try turning off some of the effects on the layers that are giving you problems to see if the effects are hogging all of the memory.