[NeoForge 1.21.1] Crash with small connector while loading back into the game

[ilkk4]

The bug
Game crashes while loading back into the world. Cannot enter the world without disabling the mod. The crashing block is a small connector attached to an electric motor.

java.lang.NullPointerException: Cannot invoke "net.neoforged.neoforge.capabilities.BlockCapabilityCache.getCapability()" because "this.external" is null

The energy network was underpowered, so the electric motor kept turning on and off while the game still worked yesterday, maybe that's a clue.

Attached a drawing of what the setup was like before the crash, cannot load into the world with the mod active.

Crash Log
minecraft_crash.txt

Reproduction
No clue how to reproduce the error I'm afraid, since this is a world that has been played for hundreds of hours by this point.

Additional context

• Mod version: createaddition-1.5.1.jar
• Forge version: Neoforge - 21.1.186
• Create version: create-1.21.1-6.0.6.jar

[ilkk4]

Might've found the cause. Checked the chunk boundaries and found out the Electric Motor is in one chunk, while the connector is in another. Disabled Concurrent Chunk Management Engine and the world becomes loadable again.

I think this might be a compability issue with the two mods.

[ilkk4]

After 15 more hours, the world has been stable. Can confirm that it was the CCME (Concurrent Chunk Management Engine) that caused the issues.