diff --git a/src/main/java/cc/carm/plugin/userprefix/hooker/UserPrefixExpansion.java b/src/main/java/cc/carm/plugin/userprefix/hooker/UserPrefixExpansion.java
index c601787..77c09a2 100644
--- a/src/main/java/cc/carm/plugin/userprefix/hooker/UserPrefixExpansion.java
+++ b/src/main/java/cc/carm/plugin/userprefix/hooker/UserPrefixExpansion.java
@@ -1,9 +1,9 @@
 package cc.carm.plugin.userprefix.hooker;
 
-import me.clip.placeholderapi.expansion.PlaceholderExpansion;
 import cc.carm.plugin.userprefix.manager.PrefixManager;
 import cc.carm.plugin.userprefix.manager.UserManager;
 import cc.carm.plugin.userprefix.model.ConfiguredPrefix;
+import me.clip.placeholderapi.expansion.PlaceholderExpansion;
 import org.bukkit.entity.Player;
 import org.bukkit.plugin.java.JavaPlugin;
 import org.jetbrains.annotations.NotNull;
@@ -36,17 +36,17 @@ public class UserPrefixExpansion extends PlaceholderExpansion {
     }
 
     @Override
-    public String getAuthor() {
+    public @NotNull String getAuthor() {
         return plugin.getDescription().getAuthors().toString();
     }
 
     @Override
-    public String getIdentifier() {
+    public @NotNull String getIdentifier() {
         return "UserPrefix";
     }
 
     @Override
-    public String getVersion() {
+    public @NotNull String getVersion() {
         return plugin.getDescription().getVersion();
     }
 
@@ -82,8 +82,10 @@ public class UserPrefixExpansion extends PlaceholderExpansion {
             case "version": {
                 return getVersion().replace("-SNAPSHOT", "");
             }
+            default: {
+                return "参数错误";
+            }
         }
-        return null;
     }
 
 }
diff --git a/src/main/java/cc/carm/plugin/userprefix/util/gui/GUI.java b/src/main/java/cc/carm/plugin/userprefix/util/gui/GUI.java
index 524faf1..7f1ddfd 100644
--- a/src/main/java/cc/carm/plugin/userprefix/util/gui/GUI.java
+++ b/src/main/java/cc/carm/plugin/userprefix/util/gui/GUI.java
@@ -194,24 +194,28 @@ public class GUI {
             Bukkit.getPluginManager().registerEvents(listener = new Listener() {
                 @EventHandler
                 public void onInventoryClickEvent(InventoryClickEvent event) {
-                    rawClickListener(event);
-                    if (!(event.getWhoClicked() instanceof Player)) {
-                        return;
-                    }
+                    if (!(event.getWhoClicked() instanceof Player)) return;
                     Player p = (Player) event.getWhoClicked();
+                    rawClickListener(event);
                     if (event.getSlot() != -999) {
                         try {
-                            if (getOpenedGUI(p) == GUI.this && event.getClickedInventory() != null && event.getClickedInventory().equals(GUI.this.inv) && GUI.this.items[event.getSlot()] != null)
+                            if (getOpenedGUI(p) == GUI.this
+                                    && event.getClickedInventory() != null
+                                    && event.getClickedInventory().equals(GUI.this.inv)
+                                    && GUI.this.items[event.getSlot()] != null) {
                                 GUI.this.items[event.getSlot()].realRawClickAction(event);
+                            }
                         } catch (ArrayIndexOutOfBoundsException e) {
+                            System.err.print("err cause by GUI(" + GUI.this + "), name=" + name);
                             e.printStackTrace();
-                            System.err.print("err cause by GUI(" + GUI.this.toString() + "), name=" + name);
                             return;
                         }
-                    } else {
-                        if (setCancelledIfClickOnOuter) event.setCancelled(true);
+                    } else if (setCancelledIfClickOnOuter) {
+                        event.setCancelled(true);
                     }
-                    if (hasOpenedGUI(p) && /*player.openedGUI.inv.equals(event.getClickedInventory())*/ getOpenedGUI(p) == GUI.this && event.getClickedInventory() != null) {
+                    if (hasOpenedGUI(p)
+                            && getOpenedGUI(p) == GUI.this
+                            && event.getClickedInventory() != null) {
                         if (event.getClickedInventory().equals(GUI.this.inv)) {
                             if (setCancelledIfClickOnTarget) event.setCancelled(true);
 
@@ -231,8 +235,8 @@ public class GUI {
                                     }
                                 }
                             }
-                        } else if (event.getClickedInventory().equals(p.getInventory())) {
-                            if (setCancelledIfClickOnSelf) event.setCancelled(true);
+                        } else if (event.getClickedInventory().equals(p.getInventory()) && setCancelledIfClickOnSelf) {
+                            event.setCancelled(true);
                         }
                     }
                 }
@@ -254,6 +258,7 @@ public class GUI {
                         if (event.getInventory().equals(inv)) {
                             HandlerList.unregisterAll(this);
                             listener = null;
+                            removeOpenedGUI(p);
                             onClose();
                         }
                     }
diff --git a/src/main/java/cc/carm/plugin/userprefix/util/gui/GUIItem.java b/src/main/java/cc/carm/plugin/userprefix/util/gui/GUIItem.java
index 200a0a2..b98150f 100644
--- a/src/main/java/cc/carm/plugin/userprefix/util/gui/GUIItem.java
+++ b/src/main/java/cc/carm/plugin/userprefix/util/gui/GUIItem.java
@@ -53,10 +53,6 @@ public class GUIItem {
         actionsIgnoreActive.add(action);
     }
 
-    public void customAction() {
-
-    }
-
     public void rawClickAction(InventoryClickEvent event) {
 
     }
@@ -65,10 +61,6 @@ public class GUIItem {
 
     }
 
-    public void customAction(Object obj) {
-
-    }
-
     /**
      * 玩家点击GUI后执行的代码
      *