Access violations after 4.16 update in USceneComponent::UpdateComponentToWorldWithParent

After updating from 4.15.3 to 4.16.2 and only modifying my code in ways that warning messages suggested, I’m running into access violations in engine code that I can repeat. I’m not building the engine from source.

One of the situations that triggers this is when, in my game, I load and unload a submap of a single persistent map, load and unload to return, and then a method in my PlayerController’s tick that handles mouse movement is called. This causes an access violation at:

UE4Editor-Engine.dll!USceneComponent::UpdateComponentToWorldWithParent(USceneComponent * Parent, FName SocketName, EUpdateTransformFlags UpdateTransformFlags, const FQuat & RelativeRotationQuat, ETeleportType Teleport) Line 508

…eventually coming from this bit from my method here:

UCameraComponent* camera = ((AACPlayerPawn*)GetPawn())->Camera;
if (camera != nullptr)
{
     camera->SetWorldRotation(GetControlRotation());
}