Help! Scenes are all corrupted

hi there.
i got a major problem…since I tweaked a material unreal keeps crashing when I try to reopen the levels.

What happens:
In my material function I reconnect nodes to a diffuse output. When the swatch is open on this diffuse output node, Unreal crashes.
When collapse this output node, Unreal stays alive until I open the levels that contain this material.

All levels are crash sensitive with these material.

now what?

Unreal 4.12.3

edit: AppendMany node is causing issues. When I do the same outside this node Unreal is not crashing. See image.

Hi Millionviews,

Can you please post any crashes you’re getting on the AnswerHub in the Bug Reports section? This way we can get these reproduced, reported, and ultimately fixed!

Please include the following information:

  • Your Call Stack from the crash reporter window that pops up.
  • Your Machine/Epic ID that is at the top of this Crash Reporter window
  • Your logs from your project > Saved > Logs folder
  • Make sure to detail any and all steps needed to reproduce the crash.
  • It’s also helpful to know whether this is occurring only in your project or if it can be reproduced in a blank project as well.

Thank you!