Render did not complete warning with "timespeed" node.

I have a comp with some footage that I am speeding up with a timespeed node (setting it to twice as fast). When I try to render it I get a warning that the render did not complete, and it has stopped before the render range.
While I am using the mac beta, I suspect it is user error and I am using the node wrong or something.
What am I doing wrong?
Thanks.
While I am using the mac beta, I suspect it is user error and I am using the node wrong or something.
What am I doing wrong?
Thanks.