Hello there! 
I'm hosting a Minecraft Tekxit PI server on Minecraft 1.12.2 on my computer and I have a little issue.
Everything was going great until one day my light in my house went down while a friend was inside the server.

The server crashed and when I came back 2 chunks swapped but everything seemed normal.
Fastforward in time my friend who was inside the server tried to come back in it but everti-me he tries to join he cannot do it and there is a crash in the server logs.

If any other friend tries to join they can, but, that friend that was inside the server when that occurred cannot join.

I tried rebooting, rebooting my modem, deleting his player data to start over and nothing works.

I'm leaving the crash logs here.

Thank you!!!

-----------------------------------------------

CRASH LOGS

 

[10:27:10] [Netty Server IO #1/INFO]: Transforming class 'gu', alias 'net.minecraft.network.NettyCompressionDecoder'
[10:27:10] [Netty Server IO #1/INFO]: Scanning method 'decode(Lio/netty/channel/ChannelHandlerContext;Lio/netty/buffer/ByteBuf;Ljava/util/List;)V'
[10:27:10] [Netty Server IO #1/INFO]: Patching constant (java.lang.Integer) 2097152
[10:27:10] [Netty Server IO #1/INFO]: Patching constant (java.lang.Integer) 2097152
[10:27:10] [Netty Server IO #1/INFO]: [com.creativemd.creativecore.transformer.CreativeTransformer:transform:49]: [littletiles] Patched net.minecraft.network.NettyCompressionDecoder ...
[10:27:13] [Server thread/ERROR]: HandshakeMessageHandler exception
java.lang.OutOfMemoryError: Java heap space
    at java.util.ArrayList.<init>(Unknown Source) ~[?:1.8.0_361]
    at com.google.common.collect.Lists.newArrayListWithCapacity(Lists.java:190) ~[minecraft_server.1.12.2.jar:?]
    at net.minecraft.nbt.NBTTagList.read(NBTTagList.java:58) ~[ge.class:?]
    at net.minecraft.nbt.NBTTagCompound.readNBT(NBTTagCompound.java:497) ~[fy.class:?]
    at net.minecraft.nbt.NBTTagCompound.read(NBTTagCompound.java:58) ~[fy.class:?]
    at net.minecraft.nbt.NBTTagCompound.readNBT(NBTTagCompound.java:497) ~[fy.class:?]
    at net.minecraft.nbt.NBTTagCompound.read(NBTTagCompound.java:58) ~[fy.class:?]
    at net.minecraft.nbt.CompressedStreamTools.read(CompressedStreamTools.java:133) ~[gi.class:?]
    at net.minecraft.nbt.CompressedStreamTools.read(CompressedStreamTools.java:88) ~[gi.class:?]
    at net.minecraft.nbt.CompressedStreamTools.readCompressed(CompressedStreamTools.java:31) ~[gi.class:?]
    at net.minecraft.world.storage.SaveHandler.getPlayerNBT(SaveHandler.java:278) ~[bfb.class:?]
    at net.minecraft.server.management.PlayerList.getPlayerNBT(PlayerList.java:340) ~[pl.class:?]
    at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher.serverInitiateHandshake(NetworkDispatcher.java:220) ~[NetworkDispatcher.class:?]
    at net.minecraftforge.fml.common.network.handshake.FMLHandshakeServerState$1.accept(FMLHandshakeServerState.java:49) ~[FMLHandshakeServerState$1.class:?]
    at net.minecraftforge.fml.common.network.handshake.HandshakeMessageHandler.userEventTriggered(HandshakeMessageHandler.java:65) ~[HandshakeMessageHandler.class:?]
    at io.netty.channel.AbstractChannelHandlerContext.invokeUserEventTriggered(AbstractChannelHandlerContext.java:329) ~[minecraft_server.1.12.2.jar:?]
    at io.netty.channel.AbstractChannelHandlerContext.invokeUserEventTriggered(AbstractChannelHandlerContext.java:315) ~[minecraft_server.1.12.2.jar:?]
    at io.netty.channel.AbstractChannelHandlerContext.fireUserEventTriggered(AbstractChannelHandlerContext.java:307) ~[minecraft_server.1.12.2.jar:?]
    at io.netty.channel.ChannelInboundHandlerAdapter.userEventTriggered(ChannelInboundHandlerAdapter.java:108) ~[minecraft_server.1.12.2.jar:?]
    at io.netty.channel.AbstractChannelHandlerContext.invokeUserEventTriggered(AbstractChannelHandlerContext.java:329) ~[minecraft_server.1.12.2.jar:?]
    at io.netty.channel.AbstractChannelHandlerContext.invokeUserEventTriggered(AbstractChannelHandlerContext.java:315) ~[minecraft_server.1.12.2.jar:?]
    at io.netty.channel.AbstractChannelHandlerContext.fireUserEventTriggered(AbstractChannelHandlerContext.java:307) ~[minecraft_server.1.12.2.jar:?]
    at io.netty.channel.ChannelInboundHandlerAdapter.userEventTriggered(ChannelInboundHandlerAdapter.java:108) ~[minecraft_server.1.12.2.jar:?]
    at io.netty.channel.AbstractChannelHandlerContext.invokeUserEventTriggered(AbstractChannelHandlerContext.java:329) ~[minecraft_server.1.12.2.jar:?]
    at io.netty.channel.AbstractChannelHandlerContext.invokeUserEventTriggered(AbstractChannelHandlerContext.java:315) ~[minecraft_server.1.12.2.jar:?]
    at io.netty.channel.AbstractChannelHandlerContext.fireUserEventTriggered(AbstractChannelHandlerContext.java:307) ~[minecraft_server.1.12.2.jar:?]
    at io.netty.channel.DefaultChannelPipeline$HeadContext.userEventTriggered(DefaultChannelPipeline.java:1352) ~[minecraft_server.1.12.2.jar:?]
    at io.netty.channel.AbstractChannelHandlerContext.invokeUserEventTriggered(AbstractChannelHandlerContext.java:329) ~[minecraft_server.1.12.2.jar:?]
    at io.netty.channel.AbstractChannelHandlerContext.invokeUserEventTriggered(AbstractChannelHandlerContext.java:315) ~[minecraft_server.1.12.2.jar:?]
    at io.netty.channel.DefaultChannelPipeline.fireUserEventTriggered(DefaultChannelPipeline.java:920) ~[minecraft_server.1.12.2.jar:?]
    at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher.insertIntoChannel(NetworkDispatcher.java:183) ~[NetworkDispatcher.class:?]
    at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher.serverToClientHandshake(NetworkDispatcher.java:154) ~[NetworkDispatcher.class:?]

The version you are using is no longer supported on this forum.

Please update to a modern version of Minecraft to receive support.

Currently supported versions are 1.19.3 (Latest), 1.19.2, and 1.18.2 (LTS).