I played for about a week with no problems prior to this. Nothing notable happened to suddenly cause this, as far as I know.
This has been happening for three days now. I've tried a dozen times. He restarted the server, and the issue still persists.
Single Player worlds are still fine.

Sometimes it gives me the in-game error:

Connection Lost
Internal Exception: io.netty.handler.codec.DecoderException: java.lang.NullPointerException: Cannot invoke "net.minecraft.client.multiplayer.ClientPacketListener.m_6198_()" because the return value of "net.minecraft.client.Minecraft.m_91403_()" is null

The Launcher's error is:

The game crashed whilst rendering block entity
Error: java.lang.NullPointerException: Cannot invoke "net.minecraft.world.entity.player.Player.m_6350_()" because "placer" is null
Exit Code: 255

With the more detailed crash report:

crash-2022-05-28_15.20.06-client.txt

I'm not very experienced with this platform or mods in general, so I apologize if I messed something up.

1: Can anyone else enter the area where you are?
2: Please upload crashlog to something like hastebin or a similar site for easy no download viewing.
3: Pray I remember to respond after you do.

1. Yes, they can. I'm the only person with this problem.
2. https://www.toptal.com/developers/hastebin/mozonimope.yaml
   Hopefully that works
3. I'm praying

Well it looks like Elemental craft is causing your issue here, see if you can get someone to remove the bad block at that location.

	Name: elementalcraft:container // sirttas.elementalcraft.block.container.ElementContainerBlockEntity
	Block: Block{elementalcraft:small_container}
	Block location: World: (72,62,-103), Section: (at 8,14,9 in 4,3,-7; chunk contains blocks 64,-64,-112 to 79,319,-97), Region: (0,-1; contains chunks 0,-32 to 31,-1, blocks 0,-64,-512 to 511,319,-1)
	Block: Block{elementalcraft:small_container}
	Block location: World: (72,62,-103), Section: (at 8,14,9 in 4,3,-7; chunk contains blocks 64,-64,-112 to 79,319,-97), Region: (0,-1; contains chunks 0,-32 to 31,-1, blocks 0,-64,-512 to 511,319,-1)```

Thank you. Breaking the container fixed the issue. After about a week the same thing happened again with a different element craft container, but my friends and I are able to fix it now.