diff --git a/NCPCompatBukkit/src/main/java/fr/neatmonster/nocheatplus/compat/bukkit/BukkitAttributeAccess.java b/NCPCompatBukkit/src/main/java/fr/neatmonster/nocheatplus/compat/bukkit/BukkitAttributeAccess.java
index 4aea09fb..4a17596e 100644
--- a/NCPCompatBukkit/src/main/java/fr/neatmonster/nocheatplus/compat/bukkit/BukkitAttributeAccess.java
+++ b/NCPCompatBukkit/src/main/java/fr/neatmonster/nocheatplus/compat/bukkit/BukkitAttributeAccess.java
@@ -10,9 +10,16 @@ import org.bukkit.entity.Player;
 
 import fr.neatmonster.nocheatplus.components.modifiers.IAttributeAccess;
 import fr.neatmonster.nocheatplus.utilities.AttribUtil;
+import fr.neatmonster.nocheatplus.utilities.ReflectionUtil;
 
 public class BukkitAttributeAccess implements IAttributeAccess {
 
+    public BukkitAttributeAccess() {
+        if (ReflectionUtil.getClass("org.bukkit.attribute.AttributeInstance") == null) {
+            throw new RuntimeException("Service not available.");
+        }
+    }
+
     private int operationToInt(final Operation operation) {
         switch (operation) {
             case ADD_NUMBER:
diff --git a/NCPCompatCB2794/src/main/java/fr/neatmonster/nocheatplus/compat/cb2794/AttributeAccess.java b/NCPCompatCB2794/src/main/java/fr/neatmonster/nocheatplus/compat/cb2794/AttributeAccess.java
index e596149f..cb69d00f 100644
--- a/NCPCompatCB2794/src/main/java/fr/neatmonster/nocheatplus/compat/cb2794/AttributeAccess.java
+++ b/NCPCompatCB2794/src/main/java/fr/neatmonster/nocheatplus/compat/cb2794/AttributeAccess.java
@@ -5,12 +5,19 @@ import org.bukkit.entity.Player;
 
 import fr.neatmonster.nocheatplus.components.modifiers.IAttributeAccess;
 import fr.neatmonster.nocheatplus.utilities.AttribUtil;
+import fr.neatmonster.nocheatplus.utilities.ReflectionUtil;
 import net.minecraft.server.v1_6_R1.AttributeInstance;
 import net.minecraft.server.v1_6_R1.AttributeModifier;
 import net.minecraft.server.v1_6_R1.GenericAttributes;
 
 public class AttributeAccess implements IAttributeAccess {
 
+    public AttributeAccess() {
+        if (ReflectionUtil.getClass("net.minecraft.server.v1_6_R1.AttributeInstance") == null) {
+            throw new RuntimeException("Service not available.");
+        }
+    }
+
     @Override
     public double getSpeedAttributeMultiplier(Player player) {
         final AttributeInstance attr = ((CraftLivingEntity) player).getHandle().a(GenericAttributes.d);
diff --git a/NCPCompatCB2808/src/main/java/fr/neatmonster/nocheatplus/compat/cb2808/AttributeAccess.java b/NCPCompatCB2808/src/main/java/fr/neatmonster/nocheatplus/compat/cb2808/AttributeAccess.java
index 8fe18b26..3ff96635 100644
--- a/NCPCompatCB2808/src/main/java/fr/neatmonster/nocheatplus/compat/cb2808/AttributeAccess.java
+++ b/NCPCompatCB2808/src/main/java/fr/neatmonster/nocheatplus/compat/cb2808/AttributeAccess.java
@@ -5,12 +5,19 @@ import org.bukkit.entity.Player;
 
 import fr.neatmonster.nocheatplus.components.modifiers.IAttributeAccess;
 import fr.neatmonster.nocheatplus.utilities.AttribUtil;
+import fr.neatmonster.nocheatplus.utilities.ReflectionUtil;
 import net.minecraft.server.v1_6_R2.AttributeInstance;
 import net.minecraft.server.v1_6_R2.AttributeModifier;
 import net.minecraft.server.v1_6_R2.GenericAttributes;
 
 public class AttributeAccess implements IAttributeAccess {
 
+    public AttributeAccess() {
+        if (ReflectionUtil.getClass("net.minecraft.server.v1_6_R2.AttributeInstance") == null) {
+            throw new RuntimeException("Service not available.");
+        }
+    }
+
     @Override
     public double getSpeedAttributeMultiplier(Player player) {
         final AttributeInstance attr = ((CraftLivingEntity) player).getHandle().getAttributeInstance(GenericAttributes.d);
diff --git a/NCPCompatCB2882/src/main/java/fr/neatmonster/nocheatplus/compat/cb2882/AttributeAccess.java b/NCPCompatCB2882/src/main/java/fr/neatmonster/nocheatplus/compat/cb2882/AttributeAccess.java
index ab83fdfb..dababf26 100644
--- a/NCPCompatCB2882/src/main/java/fr/neatmonster/nocheatplus/compat/cb2882/AttributeAccess.java
+++ b/NCPCompatCB2882/src/main/java/fr/neatmonster/nocheatplus/compat/cb2882/AttributeAccess.java
@@ -5,12 +5,19 @@ import org.bukkit.entity.Player;
 
 import fr.neatmonster.nocheatplus.components.modifiers.IAttributeAccess;
 import fr.neatmonster.nocheatplus.utilities.AttribUtil;
+import fr.neatmonster.nocheatplus.utilities.ReflectionUtil;
 import net.minecraft.server.v1_6_R3.AttributeInstance;
 import net.minecraft.server.v1_6_R3.AttributeModifier;
 import net.minecraft.server.v1_6_R3.GenericAttributes;
 
 public class AttributeAccess implements IAttributeAccess {
 
+    public AttributeAccess() {
+        if (ReflectionUtil.getClass("net.minecraft.server.v1_6_R3.AttributeInstance") == null) {
+            throw new RuntimeException("Service not available.");
+        }
+    }
+
     @Override
     public double getSpeedAttributeMultiplier(Player player) {
         final AttributeInstance attr = ((CraftLivingEntity) player).getHandle().getAttributeInstance(GenericAttributes.d);
diff --git a/NCPCompatCB2922/src/main/java/fr/neatmonster/nocheatplus/compat/cb2922/AttributeAccess.java b/NCPCompatCB2922/src/main/java/fr/neatmonster/nocheatplus/compat/cb2922/AttributeAccess.java
index c33ad971..73538fea 100644
--- a/NCPCompatCB2922/src/main/java/fr/neatmonster/nocheatplus/compat/cb2922/AttributeAccess.java
+++ b/NCPCompatCB2922/src/main/java/fr/neatmonster/nocheatplus/compat/cb2922/AttributeAccess.java
@@ -5,12 +5,19 @@ import org.bukkit.entity.Player;
 
 import fr.neatmonster.nocheatplus.components.modifiers.IAttributeAccess;
 import fr.neatmonster.nocheatplus.utilities.AttribUtil;
+import fr.neatmonster.nocheatplus.utilities.ReflectionUtil;
 import net.minecraft.server.v1_7_R1.AttributeInstance;
 import net.minecraft.server.v1_7_R1.AttributeModifier;
 import net.minecraft.server.v1_7_R1.GenericAttributes;
 
 public class AttributeAccess implements IAttributeAccess {
 
+    public AttributeAccess() {
+        if (ReflectionUtil.getClass("net.minecraft.server.v1_7_R1.AttributeInstance") == null) {
+            throw new RuntimeException("Service not available.");
+        }
+    }
+
     @Override
     public double getSpeedAttributeMultiplier(Player player) {
         final AttributeInstance attr = ((CraftLivingEntity) player).getHandle().getAttributeInstance(GenericAttributes.d);
diff --git a/NCPCompatCB3026/src/main/java/fr/neatmonster/nocheatplus/compat/cb3026/AttributeAccess.java b/NCPCompatCB3026/src/main/java/fr/neatmonster/nocheatplus/compat/cb3026/AttributeAccess.java
index 47e2b49b..d36daf2e 100644
--- a/NCPCompatCB3026/src/main/java/fr/neatmonster/nocheatplus/compat/cb3026/AttributeAccess.java
+++ b/NCPCompatCB3026/src/main/java/fr/neatmonster/nocheatplus/compat/cb3026/AttributeAccess.java
@@ -5,12 +5,19 @@ import org.bukkit.entity.Player;
 
 import fr.neatmonster.nocheatplus.components.modifiers.IAttributeAccess;
 import fr.neatmonster.nocheatplus.utilities.AttribUtil;
+import fr.neatmonster.nocheatplus.utilities.ReflectionUtil;
 import net.minecraft.server.v1_7_R2.AttributeInstance;
 import net.minecraft.server.v1_7_R2.AttributeModifier;
 import net.minecraft.server.v1_7_R2.GenericAttributes;
 
 public class AttributeAccess implements IAttributeAccess {
 
+    public AttributeAccess() {
+        if (ReflectionUtil.getClass("net.minecraft.server.v1_7_R2.AttributeInstance") == null) {
+            throw new RuntimeException("Service not available.");
+        }
+    }
+
     @Override
     public double getSpeedAttributeMultiplier(Player player) {
         final AttributeInstance attr = ((CraftLivingEntity) player).getHandle().getAttributeInstance(GenericAttributes.d);
diff --git a/NCPCompatCB3043/src/main/java/fr/neatmonster/nocheatplus/compat/cb3043/AttributeAccess.java b/NCPCompatCB3043/src/main/java/fr/neatmonster/nocheatplus/compat/cb3043/AttributeAccess.java
index 3e1b7393..7bff4a43 100644
--- a/NCPCompatCB3043/src/main/java/fr/neatmonster/nocheatplus/compat/cb3043/AttributeAccess.java
+++ b/NCPCompatCB3043/src/main/java/fr/neatmonster/nocheatplus/compat/cb3043/AttributeAccess.java
@@ -5,12 +5,19 @@ import org.bukkit.entity.Player;
 
 import fr.neatmonster.nocheatplus.components.modifiers.IAttributeAccess;
 import fr.neatmonster.nocheatplus.utilities.AttribUtil;
+import fr.neatmonster.nocheatplus.utilities.ReflectionUtil;
 import net.minecraft.server.v1_7_R3.AttributeInstance;
 import net.minecraft.server.v1_7_R3.AttributeModifier;
 import net.minecraft.server.v1_7_R3.GenericAttributes;
 
 public class AttributeAccess implements IAttributeAccess {
 
+    public AttributeAccess() {
+        if (ReflectionUtil.getClass("net.minecraft.server.v1_7_R3.AttributeInstance") == null) {
+            throw new RuntimeException("Service not available.");
+        }
+    }
+
     @Override
     public double getSpeedAttributeMultiplier(Player player) {
         final AttributeInstance attr = ((CraftLivingEntity) player).getHandle().getAttributeInstance(GenericAttributes.d);
diff --git a/NCPCompatCB3100/src/main/java/fr/neatmonster/nocheatplus/compat/cb3100/AttributeAccess.java b/NCPCompatCB3100/src/main/java/fr/neatmonster/nocheatplus/compat/cb3100/AttributeAccess.java
index ba668516..c5e42584 100644
--- a/NCPCompatCB3100/src/main/java/fr/neatmonster/nocheatplus/compat/cb3100/AttributeAccess.java
+++ b/NCPCompatCB3100/src/main/java/fr/neatmonster/nocheatplus/compat/cb3100/AttributeAccess.java
@@ -5,12 +5,19 @@ import org.bukkit.entity.Player;
 
 import fr.neatmonster.nocheatplus.components.modifiers.IAttributeAccess;
 import fr.neatmonster.nocheatplus.utilities.AttribUtil;
+import fr.neatmonster.nocheatplus.utilities.ReflectionUtil;
 import net.minecraft.server.v1_7_R4.AttributeInstance;
 import net.minecraft.server.v1_7_R4.AttributeModifier;
 import net.minecraft.server.v1_7_R4.GenericAttributes;
 
 public class AttributeAccess implements IAttributeAccess {
 
+    public AttributeAccess() {
+        if (ReflectionUtil.getClass("net.minecraft.server.v1_7_R4.AttributeInstance") == null) {
+            throw new RuntimeException("Service not available.");
+        }
+    }
+
     @Override
     public double getSpeedAttributeMultiplier(final Player player) {
         final AttributeInstance attr = ((CraftLivingEntity) player).getHandle().getAttributeInstance(GenericAttributes.d);
diff --git a/NCPCompatCBDev/src/main/java/fr/neatmonster/nocheatplus/compat/cbdev/AttributeAccess.java b/NCPCompatCBDev/src/main/java/fr/neatmonster/nocheatplus/compat/cbdev/AttributeAccess.java
index 1f54f470..8a577e06 100644
--- a/NCPCompatCBDev/src/main/java/fr/neatmonster/nocheatplus/compat/cbdev/AttributeAccess.java
+++ b/NCPCompatCBDev/src/main/java/fr/neatmonster/nocheatplus/compat/cbdev/AttributeAccess.java
@@ -5,12 +5,19 @@ import org.bukkit.entity.Player;
 
 import fr.neatmonster.nocheatplus.components.modifiers.IAttributeAccess;
 import fr.neatmonster.nocheatplus.utilities.AttribUtil;
+import fr.neatmonster.nocheatplus.utilities.ReflectionUtil;
 import net.minecraft.server.v1_10_R1.AttributeInstance;
 import net.minecraft.server.v1_10_R1.AttributeModifier;
 import net.minecraft.server.v1_10_R1.GenericAttributes;
 
 public class AttributeAccess implements IAttributeAccess {
 
+    public AttributeAccess() {
+        if (ReflectionUtil.getClass("net.minecraft.server.v1_10_R1.AttributeInstance") == null) {
+            throw new RuntimeException("Service not available.");
+        }
+    }
+
     @Override
     public double getSpeedAttributeMultiplier(Player player) {
         final AttributeInstance attr = ((CraftLivingEntity) player).getHandle().getAttributeInstance(GenericAttributes.MOVEMENT_SPEED);
diff --git a/NCPCompatSpigotCB1_8_R1/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_8_R1/AttributeAccess.java b/NCPCompatSpigotCB1_8_R1/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_8_R1/AttributeAccess.java
index dbaa9de0..aa17dbf0 100644
--- a/NCPCompatSpigotCB1_8_R1/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_8_R1/AttributeAccess.java
+++ b/NCPCompatSpigotCB1_8_R1/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_8_R1/AttributeAccess.java
@@ -5,12 +5,19 @@ import org.bukkit.entity.Player;
 
 import fr.neatmonster.nocheatplus.components.modifiers.IAttributeAccess;
 import fr.neatmonster.nocheatplus.utilities.AttribUtil;
+import fr.neatmonster.nocheatplus.utilities.ReflectionUtil;
 import net.minecraft.server.v1_8_R1.AttributeInstance;
 import net.minecraft.server.v1_8_R1.AttributeModifier;
 import net.minecraft.server.v1_8_R1.GenericAttributes;
 
 public class AttributeAccess implements IAttributeAccess {
 
+    public AttributeAccess() {
+        if (ReflectionUtil.getClass("net.minecraft.server.v1_8_R1.AttributeInstance") == null) {
+            throw new RuntimeException("Service not available.");
+        }
+    }
+
     @Override
     public double getSpeedAttributeMultiplier(Player player) {
         final AttributeInstance attr = ((CraftLivingEntity) player).getHandle().getAttributeInstance(GenericAttributes.d);
diff --git a/NCPCompatSpigotCB1_8_R2/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_8_R2/AttributeAccess.java b/NCPCompatSpigotCB1_8_R2/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_8_R2/AttributeAccess.java
index 541e99ef..d1b66d30 100644
--- a/NCPCompatSpigotCB1_8_R2/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_8_R2/AttributeAccess.java
+++ b/NCPCompatSpigotCB1_8_R2/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_8_R2/AttributeAccess.java
@@ -5,12 +5,19 @@ import org.bukkit.entity.Player;
 
 import fr.neatmonster.nocheatplus.components.modifiers.IAttributeAccess;
 import fr.neatmonster.nocheatplus.utilities.AttribUtil;
+import fr.neatmonster.nocheatplus.utilities.ReflectionUtil;
 import net.minecraft.server.v1_8_R2.AttributeInstance;
 import net.minecraft.server.v1_8_R2.AttributeModifier;
 import net.minecraft.server.v1_8_R2.GenericAttributes;
 
 public class AttributeAccess implements IAttributeAccess {
 
+    public AttributeAccess() {
+        if (ReflectionUtil.getClass("net.minecraft.server.v1_8_R2.AttributeInstance") == null) {
+            throw new RuntimeException("Service not available.");
+        }
+    }
+
     @Override
     public double getSpeedAttributeMultiplier(Player player) {
         final AttributeInstance attr = ((CraftLivingEntity) player).getHandle().getAttributeInstance(GenericAttributes.d);
diff --git a/NCPCompatSpigotCB1_8_R3/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_8_R3/AttributeAccess.java b/NCPCompatSpigotCB1_8_R3/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_8_R3/AttributeAccess.java
index ae9db58f..325b3fca 100644
--- a/NCPCompatSpigotCB1_8_R3/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_8_R3/AttributeAccess.java
+++ b/NCPCompatSpigotCB1_8_R3/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_8_R3/AttributeAccess.java
@@ -5,12 +5,19 @@ import org.bukkit.entity.Player;
 
 import fr.neatmonster.nocheatplus.components.modifiers.IAttributeAccess;
 import fr.neatmonster.nocheatplus.utilities.AttribUtil;
+import fr.neatmonster.nocheatplus.utilities.ReflectionUtil;
 import net.minecraft.server.v1_8_R3.AttributeInstance;
 import net.minecraft.server.v1_8_R3.AttributeModifier;
 import net.minecraft.server.v1_8_R3.GenericAttributes;
 
 public class AttributeAccess implements IAttributeAccess {
 
+    public AttributeAccess() {
+        if (ReflectionUtil.getClass("net.minecraft.server.v1_8_R3.AttributeInstance") == null) {
+            throw new RuntimeException("Service not available.");
+        }
+    }
+
     @Override
     public double getSpeedAttributeMultiplier(Player player) {
         final AttributeInstance attr = ((CraftLivingEntity) player).getHandle().getAttributeInstance(GenericAttributes.MOVEMENT_SPEED);
diff --git a/NCPCompatSpigotCB1_9_R1/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_9_R1/AttributeAccess.java b/NCPCompatSpigotCB1_9_R1/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_9_R1/AttributeAccess.java
index 1ba3e173..e3856834 100644
--- a/NCPCompatSpigotCB1_9_R1/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_9_R1/AttributeAccess.java
+++ b/NCPCompatSpigotCB1_9_R1/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_9_R1/AttributeAccess.java
@@ -5,12 +5,19 @@ import org.bukkit.entity.Player;
 
 import fr.neatmonster.nocheatplus.components.modifiers.IAttributeAccess;
 import fr.neatmonster.nocheatplus.utilities.AttribUtil;
+import fr.neatmonster.nocheatplus.utilities.ReflectionUtil;
 import net.minecraft.server.v1_9_R1.AttributeInstance;
 import net.minecraft.server.v1_9_R1.AttributeModifier;
 import net.minecraft.server.v1_9_R1.GenericAttributes;
 
 public class AttributeAccess implements IAttributeAccess {
 
+    public AttributeAccess() {
+        if (ReflectionUtil.getClass("net.minecraft.server.v1_9_R1.AttributeInstance") == null) {
+            throw new RuntimeException("Service not available.");
+        }
+    }
+
     @Override
     public double getSpeedAttributeMultiplier(Player player) {
         final AttributeInstance attr = ((CraftLivingEntity) player).getHandle().getAttributeInstance(GenericAttributes.MOVEMENT_SPEED);
diff --git a/NCPCompatSpigotCB1_9_R2/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_9_R2/AttributeAccess.java b/NCPCompatSpigotCB1_9_R2/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_9_R2/AttributeAccess.java
index 7f0679f7..7468ffef 100644
--- a/NCPCompatSpigotCB1_9_R2/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_9_R2/AttributeAccess.java
+++ b/NCPCompatSpigotCB1_9_R2/src/main/java/fr/neatmonster/nocheatplus/compat/spigotcb1_9_R2/AttributeAccess.java
@@ -5,12 +5,19 @@ import org.bukkit.entity.Player;
 
 import fr.neatmonster.nocheatplus.components.modifiers.IAttributeAccess;
 import fr.neatmonster.nocheatplus.utilities.AttribUtil;
+import fr.neatmonster.nocheatplus.utilities.ReflectionUtil;
 import net.minecraft.server.v1_9_R2.AttributeInstance;
 import net.minecraft.server.v1_9_R2.AttributeModifier;
 import net.minecraft.server.v1_9_R2.GenericAttributes;
 
 public class AttributeAccess implements IAttributeAccess {
 
+    public AttributeAccess() {
+        if (ReflectionUtil.getClass("net.minecraft.server.v1_9_R2.AttributeInstance") == null) {
+            throw new RuntimeException("Service not available.");
+        }
+    }
+
     @Override
     public double getSpeedAttributeMultiplier(Player player) {
         final AttributeInstance attr = ((CraftLivingEntity) player).getHandle().getAttributeInstance(GenericAttributes.MOVEMENT_SPEED);
diff --git a/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/compat/AttributeAccessFactory.java b/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/compat/AttributeAccessFactory.java
index 6d317dcc..438fafcf 100644
--- a/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/compat/AttributeAccessFactory.java
+++ b/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/compat/AttributeAccessFactory.java
@@ -22,7 +22,7 @@ public class AttributeAccessFactory {
         }
         catch (Throwable t) {}
         RegistryHelper.setupGenericInstance(new String[] {
-                "fr.neatmonster.nocheatplus.compat.cbdev",
+                "fr.neatmonster.nocheatplus.compat.cbdev.AttributeAccess",
                 "fr.neatmonster.nocheatplus.compat.spigotcb1_9_R2.AttributeAccess",
                 "fr.neatmonster.nocheatplus.compat.spigotcb1_9_R1.AttributeAccess",
                 "fr.neatmonster.nocheatplus.compat.spigotcb1_8_R3.AttributeAccess",