[BUG] <title> World doesn't open.

[Antstone2898]

Version information

itemswapper-fabric-0.6.2-1.20.6

Other relevant installed mods

No response

Expected Behavior

World opens

Actual Behavior

world loads then stops.

Reproduction Steps

Open a world
leave it.
open again.

Render engine

• Vanilla
• Sodium(optionally with Iris)
• Optifine
• VulkanMod
• Canvas
• Other

Additional information

Failed to handle packet net.minecraft.class_8733@7e997375
java.lang.IllegalArgumentException: Packet type class_9154[id=itemswapper:enableshulker] is already registered!
at net.fabricmc.fabric.impl.networking.PayloadTypeRegistryImpl.register(PayloadTypeRegistryImpl.java:58)
at dev.tr7zw.itemswapper.util.NetworkUtil.registerClientCustomPacket(NetworkUtil.java:88)
at dev.tr7zw.itemswapper.ItemSwapperMod.lambda$initModloader$16(ItemSwapperMod.java:73)
at net.fabricmc.fabric.api.client.networking.v1.ClientPlayConnectionEvents.lambda$static$0(ClientPlayConnectionEvents.java:38)
at net.fabricmc.fabric.impl.networking.client.ClientPlayNetworkAddon.invokeInitEvent(ClientPlayNetworkAddon.java:54)
at net.fabricmc.fabric.impl.networking.AbstractNetworkAddon.lateInit(AbstractNetworkAddon.java:57)
at net.minecraft.class_634.handler$cco005$fabric-networking-api-v1$initAddon(class_634.java:4023)
at net.minecraft.class_634.(class_634.java:382)
at net.minecraft.class_8674.method_52794(class_8674.java:119)
at net.minecraft.class_8733.method_53041(class_8733.java:22)
at net.minecraft.class_8733.method_11054(class_8733.java:8)
at net.minecraft.class_2600.method_11072(class_2600.java:25)
at net.minecraft.class_1255.method_18859(class_1255.java:162)
at net.minecraft.class_4093.method_18859(class_4093.java:23)
at net.minecraft.class_1255.method_16075(class_1255.java:136)
at net.minecraft.class_1255.method_5383(class_1255.java:121)
at net.minecraft.class_310.method_1523(class_310.java:1275)
at net.minecraft.class_310.method_1514(class_310.java:888)
at net.minecraft.client.main.Main.main(Main.java:265)
at net.fabricmc.loader.impl.game.minecraft.MinecraftGameProvider.launch(MinecraftGameProvider.java:470)
at net.fabricmc.loader.impl.launch.knot.Knot.launch(Knot.java:74)
at net.fabricmc.loader.impl.launch.knot.KnotClient.main(KnotClient.java:23)