- Attempt at NPE prevention related to achievements code.

forge-gui/src/main/java/forge/control/FControlGameEventHandler.java

@@ -144,6 +144,9 @@ public class FControlGameEventHandler extends IGameEventVisitor.Base<Void> {
                 ThreadUtil.invokeInGameThread(new Runnable() {
                     @Override
                     public void run() {
+                        if (GuiBase.getInterface().getGame() == null) {
+                            return;
+                        }
                         for (Player p : GuiBase.getInterface().getGame().getRegisteredPlayers()) {
                             if (p.getController().getLobbyPlayer() == GuiBase.getInterface().getGuiPlayer()) {
                                 Achievement.updateAll(p);