Issue with running a modded 1.12.2 server

And when I type /help into the console, it always types this:

[21:50:06] [Server thread/INFO] [minecraft/DedicatedServer]: An unknown error occurred while attempting to perform this command
[21:50:06] [Server thread/WARN] [minecraft/CommandHandler]: Couldn't process command: help whitelist
java.lang.IllegalArgumentException: Comparison method violates its general contract!
        at java.util.ComparableTimSort.mergeLo(ComparableTimSort.java:744) ~[?:1.8.0_312]
        at java.util.ComparableTimSort.mergeAt(ComparableTimSort.java:481) ~[?:1.8.0_312]
        at java.util.ComparableTimSort.mergeCollapse(ComparableTimSort.java:404) ~[?:1.8.0_312]
        at java.util.ComparableTimSort.sort(ComparableTimSort.java:213) ~[?:1.8.0_312]
        at java.util.Arrays.sort(Arrays.java:1312) ~[?:1.8.0_312]
        at java.util.Arrays.sort(Arrays.java:1506) ~[?:1.8.0_312]
        at java.util.ArrayList.sort(ArrayList.java:1464) ~[?:1.8.0_312]
        at java.util.Collections.sort(Collections.java:143) ~[?:1.8.0_312]
        at net.minecraft.command.CommandHelp.func_184900_a(SourceFile:116) ~[cn.class:?]
        at net.minecraft.command.CommandHelp.func_184881_a(SourceFile:71) ~[cn.class:?]
        at net.minecraft.command.CommandHandler.func_175786_a(CommandHandler.java:119) [bj.class:?]
        at net.minecraft.command.CommandHandler.func_71556_a(CommandHandler.java:91) [bj.class:?]
        at net.minecraft.server.dedicated.DedicatedServer.func_71333_ah(DedicatedServer.java:433) [nz.class:?]
        at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:398) [nz.class:?]
        at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:668) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526) [MinecraftServer.class:?]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_312]

I'd like to fix these issues. I'm open to any suggestions, including removing and adding mods. However, I'm not very experienced with these things yet... I'll appreciate any help.

The list of mods:

- AbyssalCraft (+Integration)
- AbyssalDepths
- Alchemistry
- Alib
- AmbientSounds
- Animania (+addons)
- AnvilPatch
- Aquaculture
- Aquatic Odyssey
- Astral Sorcery
- AutoRegLib
- Baubles
- Better Caves
- Better Diving
- Better Mineshafts
- Better Nether
- Betweenlands (+redstone, music)
- Bewitchment
- Bibliocraft
- Blood magic
- Bookshelf
- Botania
- Caves and Dungeons
- CodeChickenLib
- CoFHCore + CoreFHWorld
- Colytra
- Comforts
- Create
- CreativeCore
- Crimson Revelations
- CTM-MC
- Deeper in the caves 3
- Disenchanter
- Doggy Talents
- Dynamic Surroundings
- Dynamic Trees (+forestry, quark, TC, betweenlands, twilight forest, vampirism)
- Electroblob's Wizardry
- Enchantment Descriptions
- Extra Alchemy
- Extra Utils 2
- Flight Boost
- FoamFix
- Forestry
- Forgelin Continuous
- Fossils and Archaeology
- FriendlyFire
- Guide API
- HammerLib
- HWYLA
- Ice and Fire
- IvToolkit
- JEI (+bees, integration)
- LibrarianLib Continuous
- LibraryEx
- LLibrary
- MagicBees
- Matmos
- MelonLib
- Minerva Library
- MysticalLib
- Natural Pledge
- Nature's Compass
- NetherEx
- Nether Update Backport
- Not Enough IDs
- OreLib
- Patchouli
- Phosphor
- Placebo
- Progressive Bosses
- Quark
- Recurrent Complex
- Redstone Flux
- Regrowth
- Rex's Additional Structures
- RTG
- Solar Flux Reborn
- Stygian
- TCTCore
- TFSpellPack
- Thaumcraft (+additions, augmentation, jei, periphery)
- Thermal (dynamics, expansion, foundation, innovation)
- Tombstone
- Twilight Forest
- Vampirism (+integrations, needumbrellas)
- VanillaFix
- Voice Chat
- WAWLA
- Wings
- Wither Skeleton Tweaks

!spark

Thank you, this is to see why the server is lagging, yes? But I haven't really noticed lagging, just these messages in the console that are probably pointing to some kinda problem I need to get rid of. A;though my players have reported minor lagging when mining

And I can't find anything on that page that'd help with the /help command issue...

Did you run /help from the console or as a player

Idk if this is just a paper thing but /help acts differently depending on whether the console or the player calls it

Spark can diagnose other issues other than lagging

from the console
as far as i know, it runs well as a player