use impl of set

src/main/java/tsp/headdb/core/command/CommandMain.java

@@ -104,6 +104,8 @@ public class CommandMain extends HeadDBCommand implements CommandExecutor, TabCo
                         }
                     }));
                 }
+
+                main.open(player);
             }));
 
             pane.setButton(getInstance().getConfig().getInt("gui.main.meta.search.slot"), new Button(Utils.getItemFromConfig("gui.main.meta.search.item", Material.DARK_OAK_SIGN), e -> {

src/main/java/tsp/headdb/core/storage/PlayerStorage.java

@@ -4,19 +4,19 @@ import tsp.headdb.HeadDB;
 import tsp.warehouse.storage.file.SerializableFileDataManager;
 
 import java.io.File;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Map;
 import java.util.Optional;
 import java.util.UUID;
 
-public class PlayerStorage extends SerializableFileDataManager<Collection<PlayerData>> {
+public class PlayerStorage extends SerializableFileDataManager<HashSet<PlayerData>> {
 
     private final Map<UUID, PlayerData> players = new HashMap<>();
 
-    public PlayerStorage(Storage storage) {
+    public PlayerStorage(HeadDB instance, Storage storage) {
-        super(new File("data/players.data"), storage.getExecutor());
+        super(new File(instance.getDataFolder(), "data/players.data"), storage.getExecutor());
     }
 
     public void set(PlayerData data) {
@@ -42,11 +42,11 @@ public class PlayerStorage extends SerializableFileDataManager<Collection<Player
     }
 
     public void backup() {
-        save(players.values()).whenComplete((success, ex) -> HeadDB.getInstance().getLog().debug("Saved " + players.values().size() + " player data!"));
+        save(new HashSet<>(players.values())).whenComplete((success, ex) -> HeadDB.getInstance().getLog().debug("Saved " + players.values().size() + " player data!"));
     }
 
     public void suspend() {
-        Boolean saved = save(players.values())
+        Boolean saved = save(new HashSet<>(players.values()))
                 .exceptionally(ex -> {
                     HeadDB.getInstance().getLog().error("Failed to save player data! | Stack Trace: ");
                     ex.printStackTrace();

src/main/java/tsp/headdb/core/storage/Storage.java

@@ -1,5 +1,8 @@
 package tsp.headdb.core.storage;
 
+import tsp.headdb.HeadDB;
+
+import java.io.File;
 import java.util.concurrent.Executor;
 import java.util.concurrent.Executors;
 
@@ -10,7 +13,8 @@ public class Storage {
 
     public Storage(int threads) {
         executor = Executors.newFixedThreadPool(threads, HeadDBThreadFactory.FACTORY);
-        playerStorage = new PlayerStorage(this);
+        validateDataDirectory();
+        playerStorage = new PlayerStorage(HeadDB.getInstance(), this);
     }
 
     public PlayerStorage getPlayerStorage() {
@@ -21,4 +25,9 @@ public class Storage {
         return executor;
     }
 
+    private void validateDataDirectory() {
+        //noinspection ResultOfMethodCallIgnored
+        new File(HeadDB.getInstance().getDataFolder(), "data").mkdir();
+    }
+
 }

src/main/java/tsp/headdb/core/task/UpdateTask.java

@@ -18,7 +18,7 @@ public class UpdateTask implements Task {
     @Override
     public void run() {
         HeadAPI.getDatabase().update((time, heads) -> HeadDB.getInstance().getLog().debug("Fetched: " + heads.size() + " Heads | Provider: " + HeadAPI.getDatabase().getRequester().getProvider().name() + " | Time: " + time + "ms (" + TimeUnit.MILLISECONDS.toSeconds(time) + "s)"));
-        //HeadDB.getInstance().getStorage().save();
+        HeadDB.getInstance().getStorage().getPlayerStorage().backup();
         HeadDB.getInstance().getLog().debug("UpdateTask finished!");
     }