cant render my edit!!

When somebody says Edit and they are talking about an AE comp I immediately think that they are trying to make a movie instead of creating a shot.  

The first thing I would do is set your work area to the point where the render crashes, render up to that point, then reset the work area past the problem a few frames and see if you can render the problem section. If that works you can edit the two renders together and solve your problem. If that doesn't work then you have to do as Ronald K says, look at everything that is going on when the edit crashes. Start by selecting all layers and pressing the U key twice, then start turning things off or resetting properties until you find the problem. 

Anytime I render anything that is going to take a long time and may have problems I render an Image Sequence. Then if there is a problem at frame 121 I can go back and fix 121 instead of rendering the whole thing again. That may be another option.

If the crash is at the same point in time, then you should investigate the effects and layers you have that are active at the affected time. Try switching off all the effects to see if this fixes the issue. if it does, then enable one effect at a time until the problem re-occurs. The last effect you enable and a crash occurs IS the effect that is at fault.

You may want to let us know the effects you have that are active. There may be bugs/compatibility issues that someone knows about.