I found 2 recurring Yosemite/N6.5 crashes

One is when you copy something in the pianoroll editor outside the part boundaries, normally nuendo would ask if you would move the locator to fit the new notes, now it crashes without asking.

two: bounce an audio file in the main screen, always crashes nuendo now.

sometimes: after long periods of editing in the pianoroll editor, it crashes with a random copy action

hope this helps solving the issues