Can't play singleplayer with mods

[tigerstripes175]

So, I have been able to use 1.12.2 in the past with forge. And, along with this, I have been able to use pixelmon generations (the current mod im using) with it as well, but as of recently it crashes.

I enter a singleplayer world with optifine and pixelmon generations (both the right version, 1.12.2) and start playing. As soon as I do something, the game crashes and I cannot open the game again. It gives me this error message:

The game crashed whilst exception ticking world
Error: java.lang.NoClassDefFoundError: net/minecraftforge/event/world/BlockEvent$FarmlandTrampleEvent

 

not sure why it does this, please help I really want to build a world without needing to completely restart it all over again.

[Oscarita25]

can you provide a full log and which exact forge version are you using?

[tigerstripes175]

oh, sorry about that!

 

And, I have actually used different versions of forge 1.12.2 and they all do the same thing, but this specific crash report is from 1.12.2-forge1.12.2-14.23.4.2705

 

heres the full crash report

 

---- Minecraft Crash Report ----

WARNING: coremods are present:
Contact their authors BEFORE contacting forge

// Hey, that tickles! Hehehe!

Time: 5/11/19 4:12 PM
Description: Exception ticking world

java.lang.NoClassDefFoundError: net/minecraftforge/event/world/BlockEvent$FarmlandTrampleEvent
    at com.pixelmonmod.pixelmon.worldGeneration.structure.extradimensional.ExtraDimensionalInfo.processBlockEvent(ExtraDimensionalInfo.java:199)
    at com.pixelmonmod.pixelmon.worldGeneration.structure.extradimensional.ExtraDimensionalInfo.blockBlockModification(ExtraDimensionalInfo.java:191)
    at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_73_ExtraDimensionalInfo_blockBlockModification_BlockEvent.invoke(.dynamic)
    at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
    at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:182)
    at net.minecraftforge.event.ForgeEventFactory.onNeighborNotify(ForgeEventFactory.java:159)
    at net.minecraft.world.World.func_175685_c(World.java:488)
    at net.minecraft.world.World.func_175722_b(World.java:439)
    at net.minecraft.world.World.markAndNotifyBlock(World.java:380)
    at net.minecraft.world.World.func_180501_a(World.java:360)
    at net.minecraft.world.World.func_175656_a(World.java:424)
    at net.minecraft.block.BlockGrass.func_180650_b(BlockGrass.java:44)
    at net.minecraft.block.Block.func_180645_a(Block.java:508)
    at net.minecraft.world.WorldServer.func_147456_g(WorldServer.java:476)
    at net.minecraft.world.WorldServer.func_72835_b(WorldServer.java:225)
    at net.optifine.override.WorldServerOF.func_72835_b(WorldServerOF.java:39)
    at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:756)
    at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:668)
    at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:252)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526)
    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 com.pixelmonmod.pixelmon.worldGeneration.structure.extradimensional.ExtraDimensionalInfo.processBlockEvent(ExtraDimensionalInfo.java:199)
    at com.pixelmonmod.pixelmon.worldGeneration.structure.extradimensional.ExtraDimensionalInfo.blockBlockModification(ExtraDimensionalInfo.java:191)
    at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_73_ExtraDimensionalInfo_blockBlockModification_BlockEvent.invoke(.dynamic)
    at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
    at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:182)
    at net.minecraftforge.event.ForgeEventFactory.onNeighborNotify(ForgeEventFactory.java:159)
    at net.minecraft.world.World.func_175685_c(World.java:488)
    at net.minecraft.world.World.func_175722_b(World.java:439)
    at net.minecraft.world.World.markAndNotifyBlock(World.java:380)
    at net.minecraft.world.World.func_180501_a(World.java:360)
    at net.minecraft.world.World.func_175656_a(World.java:424)
    at net.minecraft.block.BlockGrass.func_180650_b(BlockGrass.java:44)
    at net.minecraft.block.Block.func_180645_a(Block.java:508)
    at net.minecraft.world.WorldServer.func_147456_g(WorldServer.java:476)
    at net.minecraft.world.WorldServer.func_72835_b(WorldServer.java:225)
    at net.optifine.override.WorldServerOF.func_72835_b(WorldServerOF.java:39)

-- Affected level --
Details:
    Level name: Mystery dungeon
    All players: 1 total; [EntityPlayerMP['tigerstripes175'/0, l='Mystery dungeon', x=23.67, y=4.00, z=17.68]]
    Chunk stats: ServerChunkCache: 322 Drop: 0
    Level seed: 6921802600105528184
    Level generator: ID 01 - flat, ver 0. Features enabled: true
    Level generator options: 3;minecraft:air;127;decoration
    Level spawn location: World: (8,4,8), Chunk: (at 8,0,8 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
    Level time: 9871 game time, 9871 day time
    Level dimension: 0
    Level storage version: 0x04ABD - Anvil
    Level weather: Rain time: 74795 (now: false), thunder time: 138937 (now: false)
    Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
    at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:756)
    at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:668)
    at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:252)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526)
    at java.lang.Thread.run(Thread.java:745)

-- System Details --
Details:
    Minecraft Version: 1.12.2
    Operating System: Windows 10 (amd64) version 10.0
    Java Version: 1.8.0_51, Oracle Corporation
    Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
    Memory: 546290816 bytes (520 MB) / 1073741824 bytes (1024 MB) up to 3221225472 bytes (3072 MB)
    JVM Flags: 8 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx3G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
    IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
    FML: MCP 9.42 Powered by Forge 14.23.4.2705 Optifine OptiFine_1.12.2_HD_U_E3 5 mods loaded, 5 mods active
    States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored

    | State     | ID        | Version      | Source                                         | Signature                                |
    |:--------- |:--------- |:------------ |:---------------------------------------------- |:---------------------------------------- |
    | UCHIJAAAA | minecraft | 1.12.2       | minecraft.jar                                  | None                                     |
    | UCHIJAAAA | mcp       | 9.42         | minecraft.jar                                  | None                                     |
    | UCHIJAAAA | FML       | 8.0.99.99    | forge-1.12.2-14.23.4.2705.jar                  | e3c3d50c7c986df74c645c0ac54639741c90a557 |
    | UCHIJAAAA | forge     | 14.23.4.2705 | forge-1.12.2-14.23.4.2705.jar                  | e3c3d50c7c986df74c645c0ac54639741c90a557 |
    | UCHIJAAAA | pixelmon  | 2.6.2        | PixelmonGenerations-1.12.2-2.6.2-universal.jar | None                                     |

    Loaded coremods (and transformers): 
    GL info: ~~ERROR~~ RuntimeException: No OpenGL context found in the current thread.
    Profiler Position: N/A (disabled)
    Player Count: 1 / 8; [EntityPlayerMP['tigerstripes175'/0, l='Mystery dungeon', x=23.67, y=4.00, z=17.68]]
    Type: Integrated Server (map_client.txt)
    Is Modded: Definitely; Client brand changed to 'fml,forge'

[Oscarita25]

try out to use the latest version of forge (most times this works for me ¯\_(ツ)_/¯)

[tigerstripes175]

ok, thank you!