This is a file bounds error that pops up when the "bounced" file will exceed the Mac OS 2 Gig file limit. This is usually caused by a break point far into the session, or a very long session. To alleviate this, highlight the area that you want to "bounce" . Click and drag in one of the timeline rulers (Bars:Beats/Mins:Secs/SMPTE) or click at the beginning of the session in one of the timeline rulers and SHIFT-Click in the same ruler where you want your "bounced" File to end.