Hey! Recently I downloaded 2 mods to my server, Decocraft and Bloodmoon. I previously had 6 other mods installed, and the server was running perfectly fine. When I downloaded these two, however, I kept getting the "Looks like you are using an unsupported modified version of the game" error message. It was saying I had coremods present, Quark and Bloodmoon. So to try to fix it, I just deleted the two that I just downloaded; I'm still getting the error message with my original mods installed. I've even tried uninstalling quark, and it's still not working Here's the crash report I'm getting.

---- Minecraft Crash Report ----

WARNING: coremods are present:
LoadingPlugin (Blood-Moon-Mod-1.12.2.jar)
LoadingPlugin (Quark-Mod-1.12.2.jar)
Contact their authors BEFORE contacting forge

// Everything's going to plan. No, really, that was supposed to happen.

Time: 2/22/19 1:28 PM
Description: Initializing game

java.lang.VerifyError: Bad return type
Exception Details:
Location:
Config.getDefiningResourcePack(Lnet/minecraft/server/network/NetHandlerLoginServer;)Lnet/minecraft/profiler/Snooper; @91: areturn
Reason:
Type 'net/minecraft/util/CombatEntry' (current frame, stack[0]) is not assignable to 'net/minecraft/profiler/Snooper' (from method signature)
Current Frame:
bci: @91
flags: { }
locals: { 'net/minecraft/server/network/NetHandlerLoginServer', 'net/minecraft/potion/PotionHealthBoost', 'java/util/Collection', 'java/util/List' }
stack: { 'net/minecraft/util/CombatEntry' }
Bytecode:
0x0000000: b202 cdb6 0388 4c2b b603 8e4d 2cc0 0335
0x0000010: 4e2d b903 3801 0004 6436 0415 049b 002e
0x0000020: 2d15 04b9 033c 0200 c003 a23a 0519 05b6
0x0000030: 03a5 3a06 1906 b203 7e2a b903 8103 0099
0x0000040: 0006 1906 b084 04ff a7ff d3b8 03a9 b203
0x0000050: 7e2a b603 d399 0007 b803 a9b0 01b0
Stackmap Table:
full_frame(@27,{Object[#665],Object[#906],Object[#915],Object[#821],Integer},{})
same_frame(@69)
chop_frame(@75,1)
same_frame(@92)

at java.lang.Class.getDeclaredFields0(Native Method)
at java.lang.Class.privateGetDeclaredFields(Class.java:2583)
at java.lang.Class.getField0(Class.java:2975)
at java.lang.Class.getField(Class.java:1701)
at net.minecraftforge.fml.client.FMLClientHandler.detectOptifine(FMLClientHandler.java:293)
at net.minecraftforge.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:216)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:467)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:378)
at net.minecraft.client.main.Main.main(SourceFile:123)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)


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

-- Head --
Thread: Client thread
Stacktrace:
at java.lang.Class.getDeclaredFields0(Native Method)
at java.lang.Class.privateGetDeclaredFields(Class.java:2583)
at java.lang.Class.getField0(Class.java:2975)
at java.lang.Class.getField(Class.java:1701)
at net.minecraftforge.fml.client.FMLClientHandler.detectOptifine(FMLClientHandler.java:293)
at net.minecraftforge.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:216)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:467)

-- Initialization --
Details:
Stacktrace:
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:378)
at net.minecraft.client.main.Main.main(SourceFile:123)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

-- 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: 305417984 bytes (291 MB) / 469762048 bytes (448 MB) up to 4294967296 bytes (4096 MB)
JVM Flags: 8 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx4G -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:
Loaded coremods (and transformers):
LoadingPlugin (Blood-Moon-Mod-1.12.2.jar)
lumien.bloodmoon.asm.ClassTransformer
LoadingPlugin (Quark-Mod-1.12.2.jar)
vazkii.quark.base.asm.ClassTransformer
Launched Version: 1.12.2-forge1.12.2-14.23.5.2807
LWJGL: 2.9.4
OpenGL: Intel(R) HD Graphics 620 GL version 4.5.0 - Build 23.20.16.4973, Intel
GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Shaders are available because OpenGL 2.1 is supported.
VBOs are available because OpenGL 1.5 is supported.

Using VBOs: Yes
Is Modded: Definitely; Client brand changed to 'fml,forge'
Type: Client (map_client.txt)
Resource Packs:
Current Language: ~~ERROR~~ NullPointerException: null
Profiler Position: N/A (disabled)
CPU: 4x Intel(R) Core(TM) i5-7200U CPU @ 2.50GHz