---- Minecraft Crash Report ----

WARNING: coremods are present:
LoadingPlugin (Quark-r1.2-104.jar)
Contact their authors BEFORE contacting forge

// This doesn't make any sense!

Time: 9/2/17 12:10 PM
Description: Exception ticking world

java.lang.NoSuchMethodError: net.minecraftforge.event.entity.living.LivingSpawnEvent$CheckSpawn.isSpawner()Z
at vazkii.quark.world.feature.NaturalBlazesInNether.onSpawn(NaturalBlazesInNether.java:58)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_31_NaturalBlazesInNether_onSpawn_CheckSpawn.invoke(.dynamic)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:179)
at net.minecraftforge.event.ForgeEventFactory.canEntitySpawn(ForgeEventFactory.java:172)
at net.minecraft.world.WorldEntitySpawner.func_77192_a(WorldEntitySpawner.java:151)
at net.minecraft.world.WorldServer.func_72835_b(WorldServer.java:202)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:750)
at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:391)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:665)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:523)
at java.lang.Thread.run(Thread.java:745)

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

-- Head --
Thread: Server thread
Stacktrace:
at vazkii.quark.world.feature.NaturalBlazesInNether.onSpawn(NaturalBlazesInNether.java:58)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_31_NaturalBlazesInNether_onSpawn_CheckSpawn.invoke(.dynamic)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:179)
at net.minecraftforge.event.ForgeEventFactory.canEntitySpawn(ForgeEventFactory.java:172)
at net.minecraft.world.WorldEntitySpawner.func_77192_a(WorldEntitySpawner.java:151)
at net.minecraft.world.WorldServer.func_72835_b(WorldServer.java:202)

-- Affected level --
Details:
Level name: world
All players: 1 total; [EntityPlayerMP['****'/313, l='world', x=27.61, y=64.00, z=-26.99]]
Chunk stats: ServerChunkCache: 625 Drop: 0
Level seed: -1878208502982338357
Level generator: ID 00 - default, ver 1. Features enabled: true
Level generator options:
Level spawn location: World: (47,64,-56), Chunk: (at 15,4,8 in 2,-4; contains blocks 32,0,-64 to 47,255,-49), Region: (0,-1; contains chunks 0,-32 to 31,-1, blocks 0,0,-512 to 511,255,-1)
Level time: 14239 game time, 1434 day time
Level dimension: 0
Level storage version: 0x04ABD - Anvil
Level weather: Rain time: 113008 (now: false), thunder time: 24520 (now: false)
Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Stacktrace:
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:750)
at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:391)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:665)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:523)
at java.lang.Thread.run(Thread.java:745)

-- System Details --
Details:
Minecraft Version: 1.12
Operating System: Linux (amd64) version 3.14.32-xxxx-grs-ipv6-64
Java Version: 1.8.0_121, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 1058701552 bytes (1009 MB) / 1513095168 bytes (1443 MB) up to 1513095168 bytes (1443 MB)
JVM Flags: 3 total; -Xmx1536M -Xms1536M -Xss2M
IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
FML: MCP 9.40 Powered by Forge 14.21.1.2387 7 mods loaded, 7 mods active
States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored
UCHIJAAAA minecraft{1.12} [Minecraft] (minecraft.jar)
UCHIJAAAA mcp{9.19} [Minecraft Coder Pack] (minecraft.jar)
UCHIJAAAA FML{8.0.99.99} [Forge Mod Loader] (forge-1.12-14.21.1.2387-universal.jar)
UCHIJAAAA forge{14.21.1.2387} [Minecraft Forge] (forge-1.12-14.21.1.2387-universal.jar)
UCHIJAAAA psi{r1.1-52} [Psi] (Psi-r1.1-52.jar)
UCHIJAAAA quark{r1.2-104} [Quark] (Quark-r1.2-104.jar)
UCHIJAAAA autoreglib{1.3-13} [AutoRegLib] (AutoRegLib-1.3-13.jar)
Loaded coremods (and transformers):
LoadingPlugin (Quark-r1.2-104.jar)
vazkii.quark.base.asm.ClassTransformer
Profiler Position: N/A (disabled)
Player Count: 1 / 30; [EntityPlayerMP['****'/313, l='world', x=27.61, y=64.00, z=-26.99]]
Is Modded: Definitely; Server brand changed to 'fml,forge'
Type: Dedicated Server (map_server.txt)

This is the server crash report. I redacted my player login name. I uploaded AutoRegLib, Quark, and Psi to the server's mods/ directory and restarted. It looked like it started up okay, but on logging in, it crashed.

Update forge.