I wasn’t able to reproduce the issue with the graveyard on my end, so my suggestion would be to add prints in the game state’s graveyard related functions to see if they are being called.
This is due to an invalid/ no player controller assigned to the player. The engine will essentially spawn a default player controller and camera at the center of the map if they are not initiated properly. Could be due to a number of reasons, but some of the most common questions:
- Are you using any plugins within your project?
- Are you incorrectly using any multicast events in your Player controllers?
This usually occurs in the editor due to some multiplayer limitations, but if this happens from a built project .exe then there may be other things at play. Feel free to send a support email to if you want to go into more project specific details of changes you have made and which could cause something like this to occur.
Looks like you have hit one of the fun engine bugs.
Did you edit the card struct or a sub-struct of the card struct in any way? The way to get things compiling again you will need to remove the struct you had edited from the card struct and compile. Then, re-add the struct back to the card struct and fix up all the link errors throughout the toolkit. This is unfortunately out of my hands and I have spoken to several people to try and get this fixed ASAP but it appears to be pushed back.
You can find more information about this issue here: Modifying a struct involved in another struct breaks all functionnalites surrounding it - Programming & Scripting - Epic Developer Community Forums
The current “fix” release is set to UE4.18. Issue link (Please Vote!): Unreal Engine Issues and Bug Tracker (UE-40050)