diff --git a/pom.xml b/pom.xml
index 4ee9306fe2..a26c52040e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -27,9 +27,9 @@
 
         <maven.settings.file>${project.basedir}/.mvn/settings.xml</maven.settings.file>
 
-        <!-- Spigot properties -->
-        <spigot.version>1.21</spigot.version>
-        <spigot.javadocs>https://hub.spigotmc.org/javadocs/spigot/</spigot.javadocs>
+        <!-- Paper properties -->
+        <paper.version>1.21</paper.version>
+        <paper.javadocs>https://papermc.io/javadocs</paper.javadocs>
     </properties>
 
     <issueManagement>
@@ -273,9 +273,9 @@
     <dependencies>
         <!-- Hard dependencies -->
         <dependency>
-            <groupId>org.spigotmc</groupId>
-            <artifactId>spigot-api</artifactId>
-            <version>${spigot.version}-R0.1-SNAPSHOT</version>
+            <groupId>io.papermc.paper</groupId>
+            <artifactId>paper-api</artifactId>
+            <version>${paper.version}-R0.1-SNAPSHOT</version>
             <scope>provided</scope>
         </dependency>
 
diff --git a/src/main/java/com/xzavier0722/mc/plugin/slimefun4/storage/controller/BlockDataController.java b/src/main/java/com/xzavier0722/mc/plugin/slimefun4/storage/controller/BlockDataController.java
index 9cae260171..a1ddfc129e 100644
--- a/src/main/java/com/xzavier0722/mc/plugin/slimefun4/storage/controller/BlockDataController.java
+++ b/src/main/java/com/xzavier0722/mc/plugin/slimefun4/storage/controller/BlockDataController.java
@@ -525,9 +525,11 @@ public void getUniversalBlockData(@Nonnull UUID uuid, IAsyncReadCallback<Slimefu
 
         var cache = loadedUniversalData.get(uuid);
 
-        return cache == null
-                ? getUniversalBlockData(uuid)
-                : (cache instanceof SlimefunUniversalBlockData ubd ? ubd : null);
+        if (cache instanceof SlimefunUniversalBlockData ubd) {
+            return ubd;
+        } else {
+            return null;
+        }
     }
 
     /**
@@ -540,7 +542,8 @@ public Optional<SlimefunUniversalBlockData> getUniversalBlockDataFromCache(@Nonn
 
         return loadedUniversalData.values().stream()
                 .filter(uniData -> uniData instanceof SlimefunUniversalBlockData ubd
-                        && ubd.getLastPresent().toLocation().equals(l))
+                        && ubd.getLastPresent() != null
+                        && l.equals(ubd.getLastPresent().toLocation()))
                 .map(data -> (SlimefunUniversalBlockData) data)
                 .findFirst();
     }
diff --git a/src/main/java/com/xzavier0722/mc/plugin/slimefun4/storage/controller/ProfileDataController.java b/src/main/java/com/xzavier0722/mc/plugin/slimefun4/storage/controller/ProfileDataController.java
index c57294ecd1..3ef46d09b8 100644
--- a/src/main/java/com/xzavier0722/mc/plugin/slimefun4/storage/controller/ProfileDataController.java
+++ b/src/main/java/com/xzavier0722/mc/plugin/slimefun4/storage/controller/ProfileDataController.java
@@ -349,7 +349,7 @@ public void run() {
                     return;
                 }
 
-                if (Bukkit.getOfflinePlayer(UUID.fromString(pUuid)).isOnline()) {
+                if (Bukkit.getOfflinePlayer(UUID.fromString(pUuid)).isConnected()) {
                     return;
                 }
 
diff --git a/src/main/java/com/xzavier0722/mc/plugin/slimefun4/storage/controller/SlimefunUniversalBlockData.java b/src/main/java/com/xzavier0722/mc/plugin/slimefun4/storage/controller/SlimefunUniversalBlockData.java
index c1b4355dd2..4c39783ce1 100644
--- a/src/main/java/com/xzavier0722/mc/plugin/slimefun4/storage/controller/SlimefunUniversalBlockData.java
+++ b/src/main/java/com/xzavier0722/mc/plugin/slimefun4/storage/controller/SlimefunUniversalBlockData.java
@@ -3,7 +3,9 @@
 import com.xzavier0722.mc.plugin.slimefun4.storage.controller.attributes.UniversalDataTrait;
 import com.xzavier0722.mc.plugin.slimefun4.storage.util.LocationUtils;
 import io.github.bakedlibs.dough.blocks.BlockPosition;
+import io.github.thebusybiscuit.slimefun4.implementation.Slimefun;
 import java.util.UUID;
+import java.util.logging.Level;
 import org.bukkit.Location;
 
 public class SlimefunUniversalBlockData extends SlimefunUniversalData {
@@ -36,7 +38,8 @@ public BlockPosition getLastPresent() {
         var data = getData("location");
 
         if (data == null) {
-            throw new IllegalArgumentException("UniversalBlockData missing location data");
+            Slimefun.logger().log(Level.WARNING, "UniversalBlockData [" + getUUID() + "] missing location data");
+            return null;
         }
 
         lastPresent = new BlockPosition(LocationUtils.toLocation(data));
diff --git a/src/main/java/io/github/thebusybiscuit/slimefun4/implementation/Slimefun.java b/src/main/java/io/github/thebusybiscuit/slimefun4/implementation/Slimefun.java
index fde30a5094..d1670f749a 100644
--- a/src/main/java/io/github/thebusybiscuit/slimefun4/implementation/Slimefun.java
+++ b/src/main/java/io/github/thebusybiscuit/slimefun4/implementation/Slimefun.java
@@ -258,6 +258,16 @@ public void onEnable() {
             // We want to ensure that the Server uses a compatible server software and have no
             // incompatible plugins
             getServer().getPluginManager().disablePlugin(this);
+        } else if (!PaperLib.isPaper()) {
+            getLogger().log(Level.WARNING, "#######################################################");
+            getLogger().log(Level.WARNING, "");
+            getLogger().log(Level.WARNING, "自 24/12/22 起 Slimefun 汉化版");
+            getLogger().log(Level.WARNING, "转为 Paper 插件, 你必须要使用 Paper");
+            getLogger().log(Level.WARNING, "或其分支才可使用 Slimefun.");
+            getLogger().log(Level.WARNING, "立即下载 Paper: https://papermc.io/downloads/paper");
+            getLogger().log(Level.WARNING, "");
+            getLogger().log(Level.WARNING, "#######################################################");
+            getServer().getPluginManager().disablePlugin(this);
         } else {
             // The Environment has been validated.
             onPluginStart();