It's a unreal engine lost due to D3D being lost
So that's related to the game losing connection with your graphics card/device. If you're using a laptop or computer with integrated graphics try changing the setting to prioritize the discrete gpu instead. Seems like UE4 has issues when the device changes. There are some other tips the internet also suggests but I would start with changing the dedicated gpu.
https://forums.unrealengine.com/t/does-anybody-know-how-to-fix-d3d-device-being-...
I've used the method written here and I haven't had D3D issues since, it might help you out too