Transcode your footage to an image sequence, Cineform, QuickTime with the Photo-JPEG codec, or some other intermediate format. See if that helps.
I returned the surface book and purchase a behmouth asus. Same issue. The issue is within after effects and keylight.
I contacted adobe.. they had no idea. I contacted keylight, no response.
I can't be the only one with this issue.
I exported from after effects to .dpx file. No audio though. It rendered much further, but again.. it crashed.
What are your memory settings?