Delete quests from the player if there are errors loading them from the db

src/main/java/emu/grasscutter/game/quest/GameMainQuest.java

@@ -346,6 +346,10 @@ public class GameMainQuest {
     public void save() {
         DatabaseHelper.saveQuest(this);
     }
+    
+    public void delete() {
+        DatabaseHelper.deleteQuest(this);
+    }
 
     public ParentQuest toProto() {
         ParentQuest.Builder proto = ParentQuest.newBuilder()

src/main/java/emu/grasscutter/game/quest/GameQuest.java

@@ -181,6 +181,7 @@ public class GameQuest {
         }
         return false;
     }
+    
     public void save() {
         getMainQuest().save();
     }

src/main/java/emu/grasscutter/game/quest/QuestManager.java

@@ -313,16 +313,27 @@ public class QuestManager extends BasePlayerManager {
     }
     public void loadFromDatabase() {
         List<GameMainQuest> quests = DatabaseHelper.getAllQuests(getPlayer());
-
+        
         for (GameMainQuest mainQuest : quests) {
+            boolean cancelAdd = false;
             mainQuest.setOwner(this.getPlayer());
 
             for (GameQuest quest : mainQuest.getChildQuests().values()) {
+                QuestData questConfig = GameData.getQuestDataMap().get(quest.getSubQuestId());
+                
+                if (questConfig == null) {
+                    mainQuest.delete();
+                    cancelAdd = true;
+                    break;
+                }
+                
                 quest.setMainQuest(mainQuest);
-                quest.setConfig(GameData.getQuestDataMap().get(quest.getSubQuestId()));
+                quest.setConfig(questConfig);
             }
 
-            this.getMainQuests().put(mainQuest.getParentQuestId(), mainQuest);
+            if (!cancelAdd) {
+                this.getMainQuests().put(mainQuest.getParentQuestId(), mainQuest);
+            }
         }
     }