After a little bit of searching in console logs, I've found that the familiar Ring will Time people out of server whenever someone places the ring in the curios slot

Steps to reproduce

Versions [Minecraft 1.20.1]
[Forge 47.1.3]
[ATM9 0.2.9]

1. Summon a Familiar (I did a dragon in this case)
2. Capture Familiar in familiar ring
3. Place Familiar ring in curios ring slot
4. People Time out

Console log

[02Nov2023 23:35:15.485] [Netty Epoll Server IO #11/ERROR] [net.minecraft.network.PacketEncoder/]: Error receiving packet 85
java.lang.NullPointerException: Cannot invoke "net.minecraft.nbt.CompoundTag.m_128471_(String)" because "compound" is null
at com.klikli_dev.occultism.common.item.tool.FamiliarRingItem$Curio.deserializeNBT(FamiliarRingItem.java:297) ~[occultism-1.20.1-1.88.1.jar%23717!/:1.88.1]
at com.klikli_dev.occultism.common.item.tool.FamiliarRingItem.getCurio(FamiliarRingItem.java:73) ~[occultism-1.20.1-1.88.1.jar%23717!/:1.88.1]
at com.klikli_dev.occultism.common.item.tool.FamiliarRingItem.getShareTag(FamiliarRingItem.java:91) ~[occultism-1.20.1-1.88.1.jar%23717!/:1.88.1]
at net.minecraftforge.common.extensions.IForgeItemStack.getShareTag(IForgeItemStack.java:378) ~[forge-1.20.1-47.1.3-universal.jar%23838!/:?]
at net.minecraft.network.FriendlyByteBuf.writeItemStack(FriendlyByteBuf.java:643) ~[server-1.20.1-20230612.114412-srg.jar%23833!/:?]
at net.minecraft.network.FriendlyByteBuf.m_130055_(FriendlyByteBuf.java:625) ~[server-1.20.1-20230612.114412-srg.jar%23833!/:?]
at net.minecraft.network.protocol.game.ClientboundSetEquipmentPacket.m_5779_(ClientboundSetEquipmentPacket.java:49) ~[server-1.20.1-20230612.114412-srg.jar%23833!/:?]
at net.minecraft.network.PacketEncoder.encode(PacketEncoder.java:45) ~[server-1.20.1-20230612.114412-srg.jar%23833!/:?]
at net.minecraft.network.PacketEncoder.encode(PacketEncoder.java:14) ~[server-1.20.1-20230612.114412-srg.jar%23833!/:?]
at io.netty.handler.codec.MessageToByteEncoder.write(MessageToByteEncoder.java:107) ~[netty-codec-4.1.82.Final.jar%2381!/:4.1.82.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:717) ~[netty-transport-4.1.82.Final.jar%2385!/:4.1.82.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:709) ~[netty-transport-4.1.82.Final.jar%2385!/:4.1.82.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:792) ~[netty-transport-4.1.82.Final.jar%2385!/:4.1.82.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:702) ~[netty-transport-4.1.82.Final.jar%2385!/:4.1.82.Final]
at io.netty.handler.codec.MessageToMessageEncoder.write(MessageToMessageEncoder.java:113) ~[netty-codec-4.1.82.Final.jar%2381!/:4.1.82.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:717) ~[netty-transport-4.1.82.Final.jar%2385!/:4.1.82.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:709) ~[netty-transport-4.1.82.Final.jar%2385!/:4.1.82.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:792) ~[netty-transport-4.1.82.Final.jar%2385!/:4.1.82.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:702) ~[netty-transport-4.1.82.Final.jar%2385!/:4.1.82.Final]
at io.netty.handler.codec.MessageToMessageEncoder.write(MessageToMessageEncoder.java:113) ~[netty-codec-4.1.82.Final.jar%2381!/:4.1.82.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:717) ~[netty-transport-4.1.82.Final.jar%2385!/:4.1.82.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeWriteAndFlush(AbstractChannelHandlerContext.java:764) ~[netty-transport-4.1.82.Final.jar%2385!/:4.1.82.Final]
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:790) ~[netty-transport-4.1.82.Final.jar%2385!/:4.1.82.Final]
at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:758) ~[netty-transport-4.1.82.Final.jar%2385!/:4.1.82.Final]
at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:808) ~[netty-transport-4.1.82.Final.jar%2385!/:4.1.82.Final]
at io.netty.channel.DefaultChannelPipeline.writeAndFlush(DefaultChannelPipeline.java:1025) ~[netty-transport-4.1.82.Final.jar%2385!/:4.1.82.Final]
at io.netty.channel.AbstractChannel.writeAndFlush(AbstractChannel.java:306) ~[netty-transport-4.1.82.Final.jar%2385!/:4.1.82.Final]
at net.minecraft.network.Connection.m_243087_(Connection.java:224) ~[server-1.20.1-20230612.114412-srg.jar%23833!/:?]
at net.minecraft.network.Connection.lambda$sendPacket$8(Connection.java:213) ~[server-1.20.1-20230612.114412-srg.jar%23833!/:?]
at io.netty.util.concurrent.AbstractEventExecutor.runTask(AbstractEventExecutor.java:174) ~[netty-common-4.1.82.Final.jar%2382!/:4.1.82.Final]
at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:167) ~[netty-common-4.1.82.Final.jar%2382!/:4.1.82.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:470) ~[netty-common-4.1.82.Final.jar%2382!/:4.1.82.Final]
at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:403) ~[netty-transport-classes-epoll-4.1.82.Final.jar%2386!/:4.1.82.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997) ~[netty-common-4.1.82.Final.jar%2382!/:4.1.82.Final]
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.82.Final.jar%2382!/:4.1.82.Final]
at java.lang.Thread.run(Thread.java:833) ~[?:?]