Whenever I try to transfer an ebook to my nook (via a macbook), it says adobe has quit unexpectedly and gives me an error code. Does not successfully transfer the ebook.

I was having the same problem using ADE 4.0.2 and Mac 10.10.1. I finally gave up and deleted ADE version 4 and reinstalled version 3.0.  Works fine, and I can check out ebooks for my Nook using ADE.