[Multiplayer] Create Trains 'disappearing' when disassembled

[TigerWalts]

Modpack

FTB One

Modpack version

2.7.0

Log Files

https://pastebin.com/HBgAuBNd

[03Jul2023 16:53:03.738] [Render thread/ERROR] [net.minecraft.util.thread.BlockableEventLoop/FATAL]: Error executing task on Client
java.lang.NullPointerException: Cannot invoke "net.minecraft.world.level.block.state.BlockState.m_60734_()" because "p_46606_" is null
	at net.minecraft.world.level.Level.m_6933_(MixinLevel.java:198) ~[client-1.19.2-20220805.130853-srg.jar%23737!/:?]
	at net.minecraft.client.multiplayer.ClientLevel.m_233653_(ClientLevel.java:134) ~[client-1.19.2-20220805.130853-srg.jar%23737!/:?]
	at net.minecraft.client.multiplayer.ClientPacketListener.m_205522_(ClientPacketListener.java:635) ~[client-1.19.2-20220805.130853-srg.jar%23737!/:?]
	at net.minecraft.network.protocol.game.ClientboundSectionBlocksUpdatePacket.m_132992_(ClientboundSectionBlocksUpdatePacket.java:72) ~[client-1.19.2-20220805.130853-srg.jar%23737!/:?]
	at net.minecraft.client.multiplayer.ClientPacketListener.m_5771_(ClientPacketListener.java:634) ~[client-1.19.2-20220805.130853-srg.jar%23737!/:?]
	at net.minecraft.network.protocol.game.ClientboundSectionBlocksUpdatePacket.m_5797_(ClientboundSectionBlocksUpdatePacket.java:64) ~[client-1.19.2-20220805.130853-srg.jar%23737!/:?]
	at net.minecraft.network.protocol.game.ClientboundSectionBlocksUpdatePacket.m_5797_(ClientboundSectionBlocksUpdatePacket.java:14) ~[client-1.19.2-20220805.130853-srg.jar%23737!/:?]
        ...

Describe the bug

When disassembling a Create Train the train entity is converted back to blocks. When the block data is sent to the client it encounters an error.

From the client point of view the train has disappeared. You cannot interact with it except for the server pushing you back if you walk into it.

You can get it to re-appear if you make the server send the block data again e.g.:

• Move far away from the chunk and come back to it
• Disconnect and re-join the server

Steps to reproduce

1. Build a Create train
2. Assemble the train and then disassemble it

Expected behaviour

The blocks to sync correctly

Screenshots

No response

Additional information

• The error doesn't happen if you run just Create
• Rubidium has a newer version that fixes a similar bug but the error doesn't happen if you add the old version

One of the other mods in the pack is causing this.

[vgrynch]

I'm having a similar issue with my custom modpack. Tried to remove sets of mods and re-add, did not help. Any time I get more than ~150-170 mods, my contraptions start to get broken and the same error appears in the logs.
I also removed any rubidium or other rendering helpers etc. Still fails.
Looks like this is some general issue related to a large number of mods, possibly in the Create mod itself.