How do I fix this crash error?

How do I fix the following 1.8.9 Crash error?

Time: 8/25/21 9:06 PM
Description: Exception in server tick loop

java.util.ConcurrentModificationException
    at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901)
    at java.util.ArrayList$Itr.next(ArrayList.java:851)
    at com.tmtravlr.potioncore.PotionCoreEventHandler.onWorldTick(PotionCoreEventHandler.java:554)
    at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_95_PotionCoreEventHandler_onWorldTick_WorldTickEvent.invoke(.dynamic)
    at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:49)
    at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:140)
    at net.minecraftforge.fml.common.FMLCommonHandler.onPostWorldTick(FMLCommonHandler.java:261)
    at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:710)
    at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:605)
    at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:281)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:481)
    at java.lang.Thread.run(Thread.java:745)

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

-- System Details --
Details:
    Minecraft Version: 1.8.9
    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: 2027039560 bytes (1933 MB) / 3892314112 bytes (3712 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: 13, tallocated: 95
    FML: MCP 9.19 Powered by Forge 11.15.1.2318 Optifine OptiFine_1.8.9_HD_U_L5 27 mods loaded, 27 mods active
    States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored
    UCHIJAAAA    mcp{9.19} [Minecraft Coder Pack] (minecraft.jar) 
    UCHIJAAAA    FML{8.0.99.99} [Forge Mod Loader] (forge-1.8.9-11.15.1.2318-1.8.9.jar) 
    UCHIJAAAA    Forge{11.15.1.2318} [Minecraft Forge] (forge-1.8.9-11.15.1.2318-1.8.9.jar) 
    UCHIJAAAA    ivtoolkit{1.2.6} [IvToolkit] (minecraft.jar) 
    UCHIJAAAA    movillages{1.5.1} [Mo' Villages] ([1.8.x]Mo'+Villages-1.5.1.jar) 
    UCHIJAAAA    ActuallyAdditions{1.8.9-r26} [Actually Additions] (ActuallyAdditions-1.8.9-r26.jar) 
    UCHIJAAAA    backpack{3.0.1} [Backpack] (backpack-3.0.1-1.8.9.jar) 
    UCHIJAAAA    birdsnests{1.3} [Bird's Nests] (BirdsNests1.8.9-1.3.jar) 
    UCHIJAAAA    Bloodmoon{1.2} [Bloodmoon] (Bloodmoon-MC1.8.8-1.4.jar) 
    UCHIJAAAA    ExtraUtils2{1.0} [ExtraUtils2] (extrautils2-1.8.9-alpha-0.0.2.jar) 
    UCHIJAAAA    HealthBar{1.0.1} [Health Bar] (HealthBar-1.8.9-1.0.1-10.jar) 
    UCHIJAAAA    mantle{1.8.9-0.9.2.jenkins102} [Mantle] (Mantle-1.8.9-0.9.2.jar) 
    UCHIJAAAA    tconstruct{1.8.9-2.2.1.jenkins1005} [Tinkers' Construct] (TConstruct-1.8.9-2.2.1.jar) 
    UCHIJAAAA    ImmersiveEngineering{0.8-32} [Immersive Engineering] (ImmersiveEngineering-0.8-32.jar) 
    UCHIJAAAA    InventoryPets{1.4.9} [Inventory Pets] (inventorypets-1.8.9-1.4.9.jar) 
    UCHIJAAAA    JEI{2.24.2.126} [Just Enough Items] (jei_1.8.9-2.24.2.126.jar) 
    UCHIJAAAA    lootplusplus{1.7.1_for_1.8.9} [Loot++] (Loot++-1.7.1_for_1.8.9 (2).jar) 
    UCHIJAAAA    lucky{7.0.2} [Lucky Block] (luckyblock-1.8.9-1-forge (1).jar) 
    UCHIJAAAA    potioncore{1.3_for_1.8.9} [Potion Core] (PotionCore-1.3_for_1.8.9 (1).jar) 
    UCHIJAAAA    ProjectE{1.8.9-PE1.1.4} [ProjectE] (ProjectE-1.8.9-PE1.1.4 (1).jar) 
    UCHIJAAAA    randomthings{3.6.6} [Random Things] (RandomThings-MC1.8.9-3.6.6.jar) 
    UCHIJAAAA    reccomplex{0.9.7.8.1} [Recurrent Complex] (RecurrentComplex-0.9.7.8.1.jar) 
    UCHIJAAAA    SoManyEnchantments{0.4.0} [Rin's So Many Enchantments] (SoManyEnchantments+Emergency(1.8.9)+V0.4.01+BETA.jar) 
    UCHIJAAAA    EnchExtensioner{0.3.0} [EnchExtensioner] (SoManyEnchantments+Emergency(1.8.9)+V0.4.01+BETA.jar) 
    UCHIJAAAA    torohealthmod{1.8.9-7} [ToroHealth Damage Indicators] (torohealth-1.8.9-7.jar) 
    UCHIJAAAA    VeinMiner{0.36.0_1.8.9-d08ea04} [Vein Miner] (VeinMiner-1.8.9-0.36.0.579+d08ea04.jar) 
    UCHIJAAAA    VeinMinerModSupport{0.36.0_1.8.9-d08ea04} [Mod Support] (VeinMiner-1.8.9-0.36.0.579+d08ea04.jar) 
    Loaded coremods (and transformers): 
LoadingPlugin (Bloodmoon-MC1.8.8-1.4.jar)
  lumien.bloodmoon.asm.ClassTransformer
CoreXU2 (extrautils2-1.8.9-alpha-0.0.2.jar)
  com.rwtema.extrautils2.asm.ClassTransformerHandler
IvToolkit (IvToolkit-1.2.6.jar)
  
LoadingPlugin (RandomThings-MC1.8.9-3.6.6.jar)
  lumien.randomthings.asm.ClassTransformer
    GL info: ~~ERROR~~ RuntimeException: No OpenGL context found in the current thread.
    Pulsar/tconstruct loaded Pulses: 
        - TinkerCommons (Enabled/Forced)
        - TinkerWorld (Enabled/Not Forced)
        - TinkerTools (Enabled/Not Forced)
        - TinkerSmeltery (Enabled/Not Forced)
        - TinkerGadgets (Enabled/Not Forced)
        - TinkerOredict (Enabled/Forced)
        - TinkerIntegration (Enabled/Forced)
        - TinkerFluids (Enabled/Forced)
        - TinkerMaterials (Enabled/Forced)

    Profiler Position: N/A (disabled)
    Player Count: 1 / 8; [EntityPlayerMP['SashaFInn07'/515, l='New World', x=540.29, y=68.00, z=-165.60]]
    Type: Integrated Server (map_client.txt)
    Is Modded: Definitely; Client brand changed to 'fml,forge'
    OptiFine Version: OptiFine_1.8.9_HD_U_L5
    OptiFine Build: 20191204-143016
    Render Distance Chunks: 8
    Mipmaps: 4
    Anisotropic Filtering: 1
    Antialiasing: 0
    Multitexture: false
    Shaders: null
    OpenGlVersion: 4.6.148201 Compatibility Profile Context 20.50.02.06 27.20.15002.6001
    OpenGlRenderer: AMD Radeon(TM) Graphics
    OpenGlVendor: ATI Technologies Inc.
    CpuCount: 6