data on BD-R unreadable
 

I always burn all of my project files onto a blu-ray as data. Anyway, I am having problems with my drive reading this paticular disc. It is not recognizing the volume, appears blank, so I can not access any files. If I try to do a disc copy in toast it will see that there are 18 gigs of data on the capacity meter but that is all, no actual files. I am on a mac and have a pioneer bdr203 drive. Is there any way of recovering these files?? Any immediate help is appreciated!

Thanks!