Avoid null pointer

src/main/java/emu/nebula/server/handlers/HandlerTowerGrowthGroupNodeUnlockReq.java

@@ -20,7 +20,7 @@ public class HandlerTowerGrowthGroupNodeUnlockReq extends NetHandler {
         var change = session.getPlayer().getStarTowerManager().unlockGrowthNodeGroup(req.getValue());
 
         if (change == null) {
-            session.encodeMsg(NetMsgId.tower_growth_group_node_unlock_failed_ack);
+            return session.encodeMsg(NetMsgId.tower_growth_group_node_unlock_failed_ack);
         }
 
         // Get list of unlocked nodes

src/main/java/emu/nebula/server/handlers/HandlerVampireSurvivorRewardSelectReq.java

@@ -19,22 +19,22 @@ public class HandlerVampireSurvivorRewardSelectReq extends NetHandler {
         var game = session.getPlayer().getVampireSurvivorManager().getGame();
 
         if (game == null) {
-            session.encodeMsg(NetMsgId.vampire_survivor_reward_select_failed_ack);
+            return session.encodeMsg(NetMsgId.vampire_survivor_reward_select_failed_ack);
         }
 
         // Select
         int cardId = game.selectReward(req.getIndex(), req.getReRoll());
 
         if (cardId <= 0) {
-            session.encodeMsg(NetMsgId.vampire_survivor_reward_select_failed_ack);
+            return session.encodeMsg(NetMsgId.vampire_survivor_reward_select_failed_ack);
         }
 
         // Build response
         var rsp = VampireSurvivorRewardSelectResp.newInstance();
 
         rsp.getMutableResp()
-            .setFateCardId(cardId)
-            .setReward(game.getRewardProto());
+                .setFateCardId(cardId)
+                .setReward(game.getRewardProto());
 
         // Encode and send
         return session.encodeMsg(NetMsgId.vampire_survivor_reward_select_succeed_ack, rsp);