Thanks! I feel so stupid. That resolved it.
I’m new to Unreal so this could be something I’m doing, but it’s totally corrupting materials I’ve made using UE4’s material system. Open up the SceneDepth material and observe that divides have no outputs and there is no outputs for Scene Depth. I don’t know how it got corrupted, I just noticed it got corrupted. This is a blueprint only project, no C++ code. I’ve tried restarting the editor and my computer system. Creating a new material also has this issue. It’s completely hosed this project. Initially output variables and divides were working.
I’ve had no crashes on this project and didn’t close the editor at all while it was saving or did anything else that may have corrupted it. Again, creating a brand new material also has this issue.
Screenshot: http://i.imgur.com/AqpyJvc.jpg
Project stripped of Starter Content. You’ll need to copy in Starter Content. (11 MB): Dropbox - File Deleted - Simplify your life
Full Project (650MB):
https://www.dropbox.com/s/m13w9hdb67pemxq/DepthRender.zip?dl=0
System:
I7-6850k
Nvidia Geforce 1070.
Win 10 64 bit.
click on that “connectors” button next to “live preview”
np 
ive been there as well.
be sure to mark the question as answered btw!