I have importing problems with Lightroom 5.6 on my MacPro. Whenever I want to import pictures from my HD into the catalog, lightroom either imports 25 or 200 pictures and then the ball keeps turning and it stops importing. I do not have these issues with this program on my 5 year old iMac, nor on my Macbook Pro. I already resetted Parameter Ram and reinstalled, but with no luck. What can I do?