diff --git a/src/main/java/net/coreprotect/CoreProtect.java b/src/main/java/net/coreprotect/CoreProtect.java
index 7530af1..9bc8a2f 100755
--- a/src/main/java/net/coreprotect/CoreProtect.java
+++ b/src/main/java/net/coreprotect/CoreProtect.java
@@ -137,8 +137,12 @@ public final class CoreProtect extends JavaPlugin {
     private static boolean performVersionChecks() {
         try {
             String[] bukkitVersion = Bukkit.getServer().getBukkitVersion().split("[-.]");
-            if (Util.newVersion(bukkitVersion[0] + "." + bukkitVersion[1], ConfigHandler.SPIGOT_VERSION)) {
-                Chat.console(Phrase.build(Phrase.VERSION_REQUIRED, "Spigot", ConfigHandler.SPIGOT_VERSION));
+            if (Util.newVersion(bukkitVersion[0] + "." + bukkitVersion[1], ConfigHandler.MINECRAFT_VERSION)) {
+                Chat.console(Phrase.build(Phrase.VERSION_REQUIRED, "Minecraft", ConfigHandler.MINECRAFT_VERSION));
+                return false;
+            }
+            if (Util.newVersion(ConfigHandler.LATEST_VERSION, bukkitVersion[0] + "." + bukkitVersion[1]) && Util.isBranch("master")) {
+                Chat.console(Phrase.build(Phrase.VERSION_INCOMPATIBLE, "Minecraft", bukkitVersion[0] + "." + bukkitVersion[1]));
                 return false;
             }
             String[] javaVersion = (System.getProperty("java.version").replaceAll("[^0-9.]", "") + ".0").split("\\.");
diff --git a/src/main/java/net/coreprotect/command/PurgeCommand.java b/src/main/java/net/coreprotect/command/PurgeCommand.java
index e6f2dd2..73f4897 100755
--- a/src/main/java/net/coreprotect/command/PurgeCommand.java
+++ b/src/main/java/net/coreprotect/command/PurgeCommand.java
@@ -104,6 +104,11 @@ public class PurgeCommand extends Consumer {
         int restrictCount = 0;
 
         if (argBlocks.size() > 0) {
+            if (!Util.validDonationKey()) {
+                Chat.sendMessage(player, Color.DARK_AQUA + "CoreProtect " + Color.WHITE + "- " + Phrase.build(Phrase.DONATION_KEY_REQUIRED));
+                return;
+            }
+
             StringBuilder includeListMaterial = new StringBuilder();
             StringBuilder includeListEntity = new StringBuilder();
 
diff --git a/src/main/java/net/coreprotect/config/ConfigHandler.java b/src/main/java/net/coreprotect/config/ConfigHandler.java
index ab13b92..50a4ec1 100644
--- a/src/main/java/net/coreprotect/config/ConfigHandler.java
+++ b/src/main/java/net/coreprotect/config/ConfigHandler.java
@@ -45,7 +45,8 @@ public class ConfigHandler extends Queue {
     public static final String EDITION_NAME = Util.getPluginName();
     public static final String COMMUNITY_EDITION = "Community Edition";
     public static final String JAVA_VERSION = "11.0";
-    public static final String SPIGOT_VERSION = "1.15";
+    public static final String MINECRAFT_VERSION = "1.15";
+    public static final String LATEST_VERSION = "1.21";
     public static String path = "plugins/CoreProtect/";
     public static String sqlite = "database.db";
     public static String host = "127.0.0.1";
diff --git a/src/main/java/net/coreprotect/language/Language.java b/src/main/java/net/coreprotect/language/Language.java
index a19004d..91f703b 100644
--- a/src/main/java/net/coreprotect/language/Language.java
+++ b/src/main/java/net/coreprotect/language/Language.java
@@ -55,6 +55,7 @@ public class Language {
         phrases.put(Phrase.DEVELOPMENT_BRANCH, "Development branch detected, skipping patch scripts.");
         phrases.put(Phrase.DIRT_BLOCK, "Placed a temporary safety block under you.");
         phrases.put(Phrase.DISABLE_SUCCESS, "Success! Disabled {0}");
+        phrases.put(Phrase.DONATION_KEY_REQUIRED, "A valid donation key is required for that command.");
         phrases.put(Phrase.ENABLE_FAILED, "{0} was unable to start.");
         phrases.put(Phrase.ENABLE_SUCCESS, "{0} has been successfully enabled!");
         phrases.put(Phrase.ENJOY_COREPROTECT, "Enjoy {0}? Join our Discord!");
@@ -232,6 +233,7 @@ public class Language {
         phrases.put(Phrase.USING_SQLITE, "Using SQLite for data storage.");
         phrases.put(Phrase.VALID_DONATION_KEY, "Valid donation key.");
         phrases.put(Phrase.VERSION_NOTICE, "Version {0} is now available.");
+        phrases.put(Phrase.VERSION_INCOMPATIBLE, "{0} {1} is not supported.");
         phrases.put(Phrase.VERSION_REQUIRED, "{0} {1} or higher is required.");
         phrases.put(Phrase.WORLD_NOT_FOUND, "World \"{0}\" not found.");
 
diff --git a/src/main/java/net/coreprotect/language/Phrase.java b/src/main/java/net/coreprotect/language/Phrase.java
index 89e487f..d99c4c3 100644
--- a/src/main/java/net/coreprotect/language/Phrase.java
+++ b/src/main/java/net/coreprotect/language/Phrase.java
@@ -38,6 +38,7 @@ public enum Phrase {
     DEVELOPMENT_BRANCH,
     DIRT_BLOCK,
     DISABLE_SUCCESS,
+    DONATION_KEY_REQUIRED,
     ENABLE_FAILED,
     ENABLE_SUCCESS,
     ENJOY_COREPROTECT,
@@ -215,6 +216,7 @@ public enum Phrase {
     USING_SQLITE,
     VALID_DONATION_KEY,
     VERSION_NOTICE,
+    VERSION_INCOMPATIBLE,
     VERSION_REQUIRED,
     WORLD_NOT_FOUND;