iMovie, code for it's crashing?

Hello,

Usually iMovie will crash if I insert a .png or use something else it doesn't like.

What can I look at on the crash report to see what the reason is?

Is there an Apple page with codes and fixes?

Thanks.

iMac OS X 10.7.5 iMovie 11 app

I was using "Sports" templ. & basic .mov clips (nothing unusual or long).