The game crashed whilst exception initializing level
Error: java.lang.IllegalArgumentException: ChunkNibbleArrays should be 2048 bytes not: 0

Context? Log?

Well i downloaded the mod and forgelin at the latest version and i crashed

log:
---- Minecraft Crash Report ----

WARNING: coremods are present:
ForgelinPlugin (Forgelin-1.8.3.jar)
Contact their authors BEFORE contacting forge

// I feel sad now :(

Time: 7/10/19 3:50 PM
Description: Exception initializing level

java.lang.IllegalArgumentException: ChunkNibbleArrays should be 2048 bytes not: 0
at net.minecraft.world.chunk.NibbleArray.(SourceFile:16)
at net.minecraft.world.chunk.storage.AnvilChunkLoader.func_75823_a(AnvilChunkLoader.java:449)
at net.minecraft.world.chunk.storage.AnvilChunkLoader.checkedReadChunkFromNBT__Async(AnvilChunkLoader.java:128)
at net.minecraft.world.chunk.storage.AnvilChunkLoader.loadChunk__Async(AnvilChunkLoader.java:92)
at net.minecraftforge.common.chunkio.ChunkIOProvider.run(ChunkIOProvider.java:70)
at net.minecraftforge.common.chunkio.ChunkIOExecutor.syncChunkLoad(ChunkIOExecutor.java:92)
at net.minecraft.world.gen.ChunkProviderServer.loadChunk(ChunkProviderServer.java:118)
at net.minecraft.world.gen.ChunkProviderServer.func_186028_c(ChunkProviderServer.java:89)
at net.minecraft.world.gen.ChunkProviderServer.func_186025_d(ChunkProviderServer.java:135)
at net.minecraft.world.World.func_72964_e(World.java:310)
at net.minecraft.world.World.func_175726_f(World.java:305)
at net.minecraft.world.World.func_180495_p(World.java:911)
at net.minecraft.world.World.func_175623_d(World.java:230)
at net.minecraft.world.World.func_184141_c(World.java:210)
at net.minecraft.world.WorldProvider.func_76566_a(WorldProvider.java:76)
at net.minecraft.world.WorldServer.func_73052_b(WorldServer.java:944)
at net.minecraft.world.WorldServer.func_72963_a(WorldServer.java:866)
at net.minecraft.server.integrated.IntegratedServer.func_71247_a(IntegratedServer.java:123)
at net.minecraft.server.integrated.IntegratedServer.func_71197_b(IntegratedServer.java:156)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:486)
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 net.minecraft.world.chunk.NibbleArray.(SourceFile:16)
at net.minecraft.world.chunk.storage.AnvilChunkLoader.func_75823_a(AnvilChunkLoader.java:449)
at net.minecraft.world.chunk.storage.AnvilChunkLoader.checkedReadChunkFromNBT__Async(AnvilChunkLoader.java:128)
at net.minecraft.world.chunk.storage.AnvilChunkLoader.loadChunk__Async(AnvilChunkLoader.java:92)
at net.minecraftforge.common.chunkio.ChunkIOProvider.run(ChunkIOProvider.java:70)
at net.minecraftforge.common.chunkio.ChunkIOExecutor.syncChunkLoad(ChunkIOExecutor.java:92)
at net.minecraft.world.gen.ChunkProviderServer.loadChunk(ChunkProviderServer.java:118)
at net.minecraft.world.gen.ChunkProviderServer.func_186028_c(ChunkProviderServer.java:89)
at net.minecraft.world.gen.ChunkProviderServer.func_186025_d(ChunkProviderServer.java:135)
at net.minecraft.world.World.func_72964_e(World.java:310)
at net.minecraft.world.World.func_175726_f(World.java:305)
at net.minecraft.world.World.func_180495_p(World.java:911)
at net.minecraft.world.World.func_175623_d(World.java:230)
at net.minecraft.world.World.func_184141_c(World.java:210)
at net.minecraft.world.WorldProvider.func_76566_a(WorldProvider.java:76)
at net.minecraft.world.WorldServer.func_73052_b(WorldServer.java:944)

-- Affected level --
Details:
Level name: New World
All players: 0 total; []
Chunk stats: ServerChunkCache: 0 Drop: 0
Level seed: 3389472193280022946
Level generator: ID 00 - default, ver 1. Features enabled: true
Level generator options:
Level spawn location: World: (0,0,0), Chunk: (at 0,0,0 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: 0 game time, 0 day time
Level dimension: 0
Level storage version: 0x04ABD - Anvil
Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
at net.minecraft.world.WorldServer.func_72963_a(WorldServer.java:866)
at net.minecraft.server.integrated.IntegratedServer.func_71247_a(IntegratedServer.java:123)
at net.minecraft.server.integrated.IntegratedServer.func_71197_b(IntegratedServer.java:156)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:486)
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: 401171536 bytes (382 MB) / 637534208 bytes (608 MB) up to 2147483648 bytes (2048 MB)
JVM Flags: 8 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx2G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
FML: MCP 9.42 Powered by Forge 14.23.5.2796 6 mods loaded, 6 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                                |
|:------ |:------------- |:------------ |:----------------------------- |:---------------------------------------- |
| LCHIJA | minecraft     | 1.12.2       | minecraft.jar                 | None                                     |
| LCHIJA | mcp           | 9.42         | minecraft.jar                 | None                                     |
| LCHIJA | FML           | 8.0.99.99    | forge-1.12.2-14.23.5.2796.jar | e3c3d50c7c986df74c645c0ac54639741c90a557 |
| LCHIJA | forge         | 14.23.5.2796 | forge-1.12.2-14.23.5.2796.jar | e3c3d50c7c986df74c645c0ac54639741c90a557 |
| LCHIJA | forgelin      | 1.8.3        | Forgelin-1.8.3.jar            | None                                     |
| LCHIJA | betterportals | 0.1.6        | betterportals-0.1.6.jar       | None                                     |

Loaded coremods (and transformers): 

ForgelinPlugin (Forgelin-1.8.3.jar)

GL info: ~~ERROR~~ RuntimeException: No OpenGL context found in the current thread.
Profiler Position: N/A (disabled)
Player Count: 0 / 8; []
Type: Integrated Server (map_client.txt)
Is Modded: Definitely; Client brand changed to 'fml,forge'

That looks more like a corrupted world than anything to do with BP. Are you sure it's related to BP?

I think because i just generated the world with no other mods

it crashed and then i tried getting in the world again and it crashed and i took the log from that

Does it load fine with BP?

I generated the world with bo and never joined without bp

That's why I'm asking if it is even related to BP (i.e. if it does not happen without BP). The crash itself just looks like an issue with forge or vanilla.

I'll try joining without

It works without bp

Please upload your world file somewhere, so I can try to reproduce it on my machine.

https://mega.nz/#F!2M4UwKKR!4D6462uOsykAtOmirDhEUQ

i'll try downloading a new version of 1.12.2 forge

My issue is resolved after i updated forge. Thanks for your help!