After upgrading to 4.16 from 4.15.3 my project crashes with this error whenever I run 2 player multiplayer with PIE.
I have a blueprint hierarchy (BaseCharacter → PlayerCharacter → [LaserCharacter, PlasmaCharacter]) that seems to be the problem. If I open either BaseCharacter or PlayerCharacter and “Refresh All Nodes” it runs fine and doesn’t crash, but this fix doesn’t last between restarts.
The crash only happens in PIE, Packaged builds of the game do not have this problem.
I’ve realized in my case, this was related to cyclical dependencies in my classes. You might want to check your reference viewer to see if you notice any cyclical dependencies to help diagnose the problem.