well seems like it wasnt a mc class

src/main/java/kassuk/addon/blackout/mixins/MixinDefaultChannelPipeline.java → src/main/java/kassuk/addon/blackout/mixins/MixinClientConnection.java

@@ -1,24 +1,23 @@
 package kassuk.addon.blackout.mixins;
 
-import io.netty.channel.ChannelFuture;
-import io.netty.channel.DefaultChannelPipeline;
 import kassuk.addon.blackout.modules.PacketLogger;
 import meteordevelopment.meteorclient.systems.modules.Modules;
+import net.minecraft.network.ClientConnection;
+import net.minecraft.network.PacketCallbacks;
 import net.minecraft.network.packet.Packet;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.Unique;
 import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Inject;
-import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 
-@Mixin(DefaultChannelPipeline.class)
-public class MixinDefaultChannelPipeline {
+@Mixin(ClientConnection.class)
+public class MixinClientConnection {
     @Unique private PacketLogger packetLogger = null;
 
-    @Inject(method = "write(Ljava/lang/Object;)Lio/netty/channel/ChannelFuture;", at = @At("HEAD"))
-    private void writePacket(Object msg, CallbackInfoReturnable<ChannelFuture> cir) {
+    @Inject(method = "sendInternal", at = @At("HEAD"))
+    private void onSent(Packet<?> packet, PacketCallbacks callbacks, boolean flush, CallbackInfo ci) {
         if (packetLogger == null) packetLogger = Modules.get().get(PacketLogger.class);
-        else if (msg instanceof Packet<?> packet && packetLogger.isActive())
-            packetLogger.onSent(packet);
+        else if (packetLogger.isActive()) packetLogger.onSent(packet);
     }
 }

src/main/java/kassuk/addon/blackout/utils/BOInvUtils.java

@@ -49,7 +49,7 @@ public static boolean invSwitch(int slot) {
                 handler.getRevision(), PlayerInventory.MAIN_SIZE + Managers.HOLDING.slot,
                 slot, SlotActionType.SWAP, handler.getSlot(slot).getStack(), stack)
             );
-            ((IClientPlayerInteractionManager) mc.interactionManager).syncSelected();
+            ((IClientPlayerInteractionManager) mc.interactionManager).meteor$syncSelected();
             slots = new int[]{slot, Managers.HOLDING.slot};
             return true;
         }
@@ -65,6 +65,6 @@ public static void swapBack() {
             handler.getRevision(), PlayerInventory.MAIN_SIZE + slots[1],
             slots[0], SlotActionType.SWAP, handler.getSlot(slots[0]).getStack().copy(), stack)
         );
-        ((IClientPlayerInteractionManager) mc.interactionManager).syncSelected();
+        ((IClientPlayerInteractionManager) mc.interactionManager).meteor$syncSelected();
     }
 }

src/main/resources/blackout.mixins.json

@@ -27,7 +27,6 @@
     "defaultRequire": 1
   },
   "mixins": [
-    "MixinClientConnection",
-    "MixinDefaultChannelPipeline"
+    "MixinClientConnection"
   ]
 }