Can't export slideshow as video due to "Unknown error"

I use lightroom to edit the timelapses I shoot and it works brilliantly with the sync setting. But my problem is I use presets that call for the slideshow to move at 24 fps, 26fps, 30fps etc. and some of these time lapses contain over 300 photos and whenever I try to export the timelapse as a video from the slideshow module about an 8th of the way into the progress bar it stops and a message comes up that says "unknown error occurred" So my question would be: Is there a maximum number of slides you can have in a slideshow and is that what's causing this to happen? and if not what is it?

ASAP responses very much appreciated,

                                   -Noah