Seems like mcpitanlib-2.3.9-1.21-fabric broke compatibility again.

https://pastebin.com/qpNtPEZ5

uploaded the latest MCPitanLib.

Same here, Fabric 1.21 server with latest fabric version.

[08:37:30] [Server thread/INFO]: Fly0ver joined the game
[08:37:30] [Server thread/ERROR]: Couldn't place player in world
java.lang.NullPointerException: Cannot invoke "net.minecraft.class_9139.encode(Object, Object)" because "codec" is null
at dev.architectury.impl.NetworkAggregator.collectPackets(NetworkAggregator.java:146) ~[architectury-13.0.6-fabric.jar:?]
at dev.architectury.networking.NetworkManager.collectPackets(NetworkManager.java:137) ~[architectury-13.0.6-fabric.jar:?]
at dev.architectury.networking.NetworkManager.sendToPlayer(NetworkManager.java:157) ~[architectury-13.0.6-fabric.jar:?]
at net.pitan76.mcpitanlib.api.network.ServerNetworking.send(ServerNetworking.java:31) ~[mcpitanlib-2.4.0-1.21-fabric.jar:?]
at net.pitan76.itemalchemy.EMCManager.syncS2C_emc_map(EMCManager.java:307) ~[itemalchemy-0.9.1.jar:?]
at net.pitan76.itemalchemy.ItemAlchemy.lambda$init$0(ItemAlchemy.java:56) ~[itemalchemy-0.9.1.jar:?]
at java.base/java.lang.invoke.MethodHandle.invokeWithArguments(MethodHandle.java:733) ~[?:?]
at dev.architectury.event.EventFactory.invokeMethod(EventFactory.java:53) ~[architectury-13.0.6-fabric.jar:?]
at dev.architectury.event.EventFactory$1.handleInvocation(EventFactory.java:62) ~[architectury-13.0.6-fabric.jar:?]
at com.google.common.reflect.AbstractInvocationHandler.invoke(AbstractInvocationHandler.java:87) ~[guava-32.1.2-jre.jar:?]
at jdk.proxy2/jdk.proxy2.$Proxy203.join(Unknown Source) ~[?:?]
at net.minecraft.class_3324.handler$zgf000$architectury$placeNewPlayer(class_3324.java:2009) ~[server-intermediary.jar:?]
at net.minecraft.class_3324.method_14570(class_3324.java:288) ~[server-intermediary.jar:?]
at net.minecraft.class_8610.mixinextras$bridge$method_14570$45(class_8610.java) ~[server-intermediary.jar:?]
at net.minecraft.class_8610.wrapOperation$dhk000$polymer-networking$polymerNet$prePlayHandshakeHackfest(class_8610.java:1038) ~[server-intermediary.jar:?]
at net.minecraft.class_8610.method_52408(class_8610.java:152) ~[server-intermediary.jar:?]
at net.minecraft.class_8736.method_53043(class_8736.java:22) ~[server-intermediary.jar:?]
at net.minecraft.class_8736.method_11054(class_8736.java:8) ~[server-intermediary.jar:?]
at net.minecraft.class_2600.method_11072(class_2600.java:27) ~[server-intermediary.jar:?]
at net.minecraft.class_3738.run(class_3738.java:18) ~[server-intermediary.jar:?]
at net.minecraft.class_1255.method_18859(class_1255.java:162) ~[server-intermediary.jar:?]
at net.minecraft.class_4093.method_18859(class_4093.java:23) ~[server-intermediary.jar:?]
at net.minecraft.server.MinecraftServer.method_24306(MinecraftServer.java:864) ~[server-intermediary.jar:?]
at net.minecraft.server.MinecraftServer.method_18859(MinecraftServer.java:173) ~[server-intermediary.jar:?]
at net.minecraft.class_1255.method_16075(class_1255.java:136) ~[server-intermediary.jar:?]
at net.minecraft.server.MinecraftServer.method_20415(MinecraftServer.java:846) ~[server-intermediary.jar:?]
at net.minecraft.server.MinecraftServer.method_16075(MinecraftServer.java:840) ~[server-intermediary.jar:?]
at net.minecraft.class_1255.method_18857(class_1255.java:145) ~[server-intermediary.jar:?]
at net.minecraft.server.MinecraftServer.method_18857(MinecraftServer.java:810) ~[server-intermediary.jar:?]
at net.minecraft.server.MinecraftServer.method_16208(MinecraftServer.java:815) ~[server-intermediary.jar:?]
at net.minecraft.server.MinecraftServer.method_29741(MinecraftServer.java:702) ~[server-intermediary.jar:?]
at net.minecraft.server.MinecraftServer.method_29739(MinecraftServer.java:281) ~[server-intermediary.jar:?]
at java.base/java.lang.Thread.run(Thread.java:1583) [?:?]
[08:37:30] [Server thread/INFO]: Fly0ver lost connection: Invalid player data
[08:37:30] [Server thread/INFO]: Fly0ver left the game

Now working fine on the 1.21 server, however, can we have an item that will link EMC storage with our external storage like Tom's Storage? An example will be mod "EMC Link" which is for ProjectE on forge.

Mod is loading fine, but it refuses to remember a player's learned recipes and stored EMC values.

uploaded the latest MCPitanLib.

Fixed. thank you very much.
MCPitanLib: 2.4.4