global snapshot is crashing nuendo

as my sessions get larger, global snap shot is not working anymore. And now when I try it it’s crashing n5.

Here’s a typical reason I’ll use it.

repeating backgrounds: Same location, same angle, different scene. I roll to the first scene, global snapshot. Then I roll to the new scene and take every track out of read/write except the background track I want to effect.

I wrap my locators, I put N5 into preview, I apply the snapshot. then I select punch on play - to loop - N5 crashes.

This is pretty much the same way I’ve used it on smaller sessions, and this session really isn’t all that big. Why is this happening?