(except from the log file - it's >600MB - the same stack trace repeats a lot - directly after loading the world)
[07:47:26] [Server thread/FATAL] [FML]: ---- Minecraft Crash Report ----

WARNING: coremods are present:
CTMCorePlugin (CTM-MC1.12-0.2.3.12.jar)
EnderCorePlugin (EnderCore-1.12.2-0.5.20.jar)
BedPatch (bedpatch-2.2-1.12.2.jar)
MicdoodlePlugin (MicdoodleCore-1.12.2-4.0.1.170.jar)
OpenModsCorePlugin (OpenModsLib-1.12.2-0.11.5.jar)
AstralCore (astralsorcery-1.12.2-1.8.5.jar)
LoadingPlugin (Quark-r1.4-123.jar)
Do not report to Forge! Remove FoamFixAPI (or replace with FoamFixAPI-Lawful) and try again. (foamfix-0.9.7-1.12.2-anarchy.jar)
Plugin (NotEnoughIDs-1.5.4.2.jar)
ShetiPhian-ASM (shetiphiancore-1.12.0-3.5.6.jar)
FMLPlugin (elulib-0.1.12.jar)
ModFixLC (ModFix-1.12.2-1.0.0.1.jar)
Inventory Tweaks Coremod (InventoryTweaks-1.64-dev.jar)
ForgelinPlugin (Forgelin-1.6.0.jar)
LoadingPlugin (RandomThings-MC1.12.2-4.1.5.jar)
TransformerLoader (OpenComputers-MC1.12.2-1.7.2.67.jar)
AppleCore (AppleCore-mc1.12.2-3.1.1.jar)
IELoadingPlugin (ImmersiveEngineering-0.12-80-core.jar)
Contact their authors BEFORE contacting forge

// Quite honestly, I wouldn't worry myself about that.

Description: Ticking block entity

java.lang.NullPointerException: The validated object is null
at org.apache.commons.lang3.Validate.notNull(Validate.java:225)
at org.apache.commons.lang3.Validate.notNull(Validate.java:206)
at net.minecraft.util.NonNullList.add(SourceFile:56)
at java.util.AbstractList.add(AbstractList.java:108)
at mekanism.common.tile.TileEntityMultiblock.getNetworkedData(TileEntityMultiblock.java:208)
at mekanism.common.tile.TileEntityInductionCasing.getNetworkedData(TileEntityInductionCasing.java:83)
at mekanism.common.tile.TileEntityMultiblock.onUpdate(TileEntityMultiblock.java:130)
at mekanism.common.tile.TileEntityInductionCasing.onUpdate(TileEntityInductionCasing.java:48)
at mekanism.common.tile.prefab.TileEntityBasicBlock.func_73660_a(TileEntityBasicBlock.java:80)
at net.minecraft.world.World.func_72939_s(World.java:1832)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:613)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:765)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:666)
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:185)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:524)
at java.lang.Thread.run(Thread.java:748)

A detailed walkthrough of the error, its code path and all known details is as follows:

-- Head --
Thread: Server thread
Stacktrace:
at org.apache.commons.lang3.Validate.notNull(Validate.java:225)
at org.apache.commons.lang3.Validate.notNull(Validate.java:206)
at net.minecraft.util.NonNullList.add(SourceFile:56)
at java.util.AbstractList.add(AbstractList.java:108)
at mekanism.common.tile.TileEntityMultiblock.getNetworkedData(TileEntityMultiblock.java:208)
at mekanism.common.tile.TileEntityInductionCasing.getNetworkedData(TileEntityInductionCasing.java:83)
at mekanism.common.tile.TileEntityMultiblock.onUpdate(TileEntityMultiblock.java:130)
at mekanism.common.tile.TileEntityInductionCasing.onUpdate(TileEntityInductionCasing.java:48)
at mekanism.common.tile.prefab.TileEntityBasicBlock.func_73660_a(TileEntityBasicBlock.java:80)

-- Block entity being ticked --
Details:
Name: minecraft:inductioncasing // mekanism.common.tile.TileEntityInductionCasing
Block type: ID #2969 (tile.BasicBlock2 // null)
Block data value: 1 / 0x1 / 0b0001
Block location: World: (-1062,86,-1029), Chunk: (at 10,5,11 in -67,-65; contains blocks -1072,0,-1040 to -1057,255,-1025), Region: (-3,-3; contains chunks -96,-96 to -65,-65, blocks -1536,0,-1536 to -1025,255,-1025)
Actual block type: ID #2969 (tile.BasicBlock2 // null)
Actual block data value: 1 / 0x1 / 0b0001
Stacktrace:
at net.minecraft.world.World.func_72939_s(World.java:1832)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:613)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:765)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:666)
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:185)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:524)
at java.lang.Thread.run(Thread.java:748)
-- System Details --
Details:
Minecraft Version: 1.12.2
Operating System: Linux (amd64) version 4.13.0-38-generic
Java Version: 1.8.0_162, Oracle Corporation
Java VM Version: OpenJDK 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 3658156384 bytes (3488 MB) / 7916421120 bytes (7549 MB) up to 12871532544 bytes (12275 MB)
JVM Flags: 6 total; -Xmx12G -Xms4G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
FML: MCP 9.42 Powered by Forge 14.23.3.2668 280 mods loaded, 280 mods active

(the game did NOT crash - it kept running and generating these messages over and over)

Steps to reproduce:

I have a 5x5x3 induction matrix with 1 basic provider (25KRF/t) and 4 advanced cells in it. The matrix has 8 ports on the top, 4 as input, 4 as output all wired up using Immersive Engineering HV connectors.

I noticed after some time in the world (single player) that everything was out of power and no input/output was happening (statistics in the matrix was 0/0 powered stored was what I expected).

Then I broke one casing block and placed it back (not one of the ports) - at that point everything worked again (except the input/output statistic which randomly was showing 25KRF I/O - even so with 4x HV connector that shouldn't be possible - and the energy stored was increasing correctly - so I think there might be an issue with the statistic).

From the time stamps in the log the messages seem to have stopped after breaking and replacing the casing.

Version (make sure you are on the latest version before reporting):

forge-1.12.2-14.23.3.2668
Mekanism-1.12.2-9.4.3.330
MekanismGenerators-1.12.2-9.4.3.330
MekanismTools-1.12.2-9.4.3.330
ImmersiveEngineering-0.12-80

If a (crash)log is relevant for this issue, link it here: (It's almost always relevant)

Sadly the log is too big up upload - but I'll keep it around and can try to extract further parts if needed/possible.

I haven't found any other report - can you link the issue here?

#4972

(it was closed automatically by github when a merge to master was done but the server's commit hook is broken so no release was made)

PS: The induction matrix has at least 3 blocks on each side to a chunk boundary - and no chunk loader is active.

already been reported multiple times, wait for next release