Power Fist Customization Crashing Client

[Mad-Matti]

Version info
Java version: 1.8.0_51
Minecraft Forge version: 14.23.5.2838

Describe the bug
Playing on a friend's server, with allowPowerFistCustomization set to true, upon clicking the PowerFist in the Visual tab the game crashes.

Mod list
FML | 8.0.99.99 | forge-1.12.2-14.23.5.2838.jar
forge | 14.23.5.2838 | forge-1.12.2-14.23.5.2838.jar
aether_legacy | 1.4.4 | aether_legacy-1.12.2-v1.4.4.jar
aether_legacy_addon | 1.12.2-v1.2.3 | aether_continuation-1.12.2-v1.2.3.jar
biomesoplenty | 7.0.1.2439 | BiomesOPlenty-1.12.2-7.0.1.2439-universal.jar
craftstudioapi | 1.0.0 | CraftStudioAPI-universal-1.0.1.95-mc1.12-alpha.jar
harvestcraft | 1.12.2zb | Pam's+HarvestCraft+1.12.2zf.jar
ctm | MC1.12.2-0.3.3.22 | CTM-MC1.12.2-0.3.3.22.jar
baubles | 1.5.2 | Baubles-1.12-1.5.2.jar
thaumcraft | 6.1.BETA26 | Thaumcraft-1.12.2-6.1.BETA26.jar
twilightforest | 3.9.984 | twilightforest-1.12.2-3.9.984-universal.jar
animania | 1.6.2 | animania-1.12.2-1.6.2.jar
jei | 4.15.0.268 | jei_1.12.2-4.15.0.268.jar
appleskin | 1.0.9 | AppleSkin-mc1.12-1.0.9.jar
mantle | 1.12-1.3.3.55 | Mantle-1.12-1.3.3.55.jar
chisel | MC1.12.2-0.2.1.35 | Chisel-MC1.12.2-0.2.1.35.jar
tconstruct | 1.12.2-2.12.0.157 | TConstruct-1.12.2-2.12.0.157.jar
conarm | 1.2.4 | conarm-1.12.2-1.2.4.jar
armoryexpansion | 1.3.3 | armoryexpansion-1.3.3.jar
armoryexpansion-custommaterials | 1.3.3 | armoryexpansion-1.3.3.jar
llibrary | 1.7.19 | llibrary-1.7.19-1.12.2.jar
iceandfire | 1.8.1 | iceandfire-1.8.1.jar
armoryexpansion-iceandfire | 1.3.3 | armoryexpansion-1.3.3.jar
armoryexpansion-matteroverdrive | 1.3.3 | armoryexpansion-1.3.3.jar
attributefix | 1.0.4 | AttributeFix-1.12.2-1.0.4.jar
quark | r1.6-177 | Quark-r1.6-177.jar
autoreglib | 1.3-32 | AutoRegLib-1.3-32.jar
mmdlib | 1.0.0-rc2 | MMDLib-1.12-1.0.0-rc2.36.jar
basemetals | 2.5.0-rc2 | BaseMetals-1.12-2.5.0-rc2.332.jar
bibliocraft | 2.4.5 | BiblioCraft[v2.4.5][MC1.12.2].jar
forgelin | 1.8.3 | Forgelin-1.8.3.jar
bountiful | 2.2.0 | Bountiful-2.2.0.jar
chameleon | 1.12-4.1.3 | Chameleon-1.12-4.1.3.jar
chargers | 1.2.0.4 | Chargers-1.12.2-1.2.0.4.jar
chesttransporter | 2.8.8 | ChestTransporter-1.12.2-2.8.8.jar
craftablenametag | 1.0.0 | CN+(MC+1.12.2).jar
colytra | 1.2.0.3 | colytra-1.12.2-1.2.0.3.jar
extendedrenderer | v1.0 | coroutil-1.12.1-1.2.32.jar
coroutil | 1.12.1-1.2.32 | coroutil-1.12.1-1.2.32.jar
configmod | v1.0 | coroutil-1.12.1-1.2.32.jar
cosmeticarmorreworked | 1.12.2-v4a | CosmeticArmorReworked-1.12.2-v4a.jar
corpsecomplex | 1.0.6 | corpsecomplex-1.12.2-1.0.6.jar
craftelytra | 1.2 | CraftableElytra-1.1.jar
cns | 1.0 | CraftingNetherStar1.12.1-1.1.jar
creeperconfetti | 1.4.2 | creeperconfetti-1.4.2.jar
dirt2path | 1.7.1 | dirt2path-1.8.0.jar
disenchanter | 1.6 | disenchanter-1.121.6.jar
effortlessbuilding | 1.12.2-2.13 | effortlessbuilding-1.12.2-2.13.jar
enderhopper | 1.0.1 | enderhopper-1.12.2-1.0.1.jar
modernmetals | 2.5.0-rc2 | ModernMetals-1.12-2.5.0-rc2.152.jar
endmetals | 1.2.0-rc2 | EndMetals-1.12-1.2.0-rc2.67.jar
equaldragons | 1.1 | EqualDragons-1.1.jar
familiarfauna | 1.0.11 | FamiliarFauna-1.12.2-1.0.11.jar
forestry | 5.8.1.322 | forestry_1.12.2-5.8.1.322.jar
fossil | 8.0.2 | fossilsarcheology-8.0.2.jar | None |
minecraftfuture | 0.1.9 | future-mc-0.1.10.jar
grimoireofgaia | 1.6.9.3 | GrimoireOfGaia3-1.12.2-1.6.9.3.jar
waila | 1.8.26 | Hwyla-1.8.26-B41_1.12.2.jar | None |
improvedbackpacks | 1.12.2-1.4.0.0 | ImprovedBackpacks-1.12.2-1.4.0.0.jar
inventorytweaks | 1.63+release.109.220f184 | InventoryTweaks-1.63.jar
journeymap | 1.12.2-5.5.5 | journeymap-1.12.2-5.5.5.jar | None |
malisiscore | 1.12.2-6.5.1-SNAPSHOT | malisiscore-1.12.2-6.5.1.jar
malisisblocks | 1.12.2-6.1.0 | malisisblocks-1.12.2-6.1.0.jar
malisisdoors | 1.12.2-7.3.0 | malisisdoors-1.12.2-7.3.0.jar
mekanism | 1.12.2-9.8.1.383 | Mekanism-1.12.2-9.8.1.383(1).jar
mekanismgenerators | 1.12.2-9.8.1.383 | MekanismGenerators-1.12.2-9.8.1.383.jar
mekanismtools | 1.12.2-9.8.1.383 | MekanismTools-1.12.2-9.8.1.383.jar
moartinkers | 0.6.0 | moartinkers-0.6.0.jar
numina | 1.12.2-1.0.38 | Numina-1.12.2-1.0.38.jar
powersuits | 1.12.2-1.0.46 | ModularPowersuits-1.12.2-1.0.46.jar
mousetweaks | 2.10 | MouseTweaks-2.10-mc1.12.2.jar
mowziesmobs | 1.5.4 | mowziesmobs-1.5.4.jar
multimob | 1.0.5 | multimob-1.0.5.jar
multiplelights | 1.0.2 | MultipleLights-1.12.x-1.0.2.jar
nethermetals | 1.2.0-rc2 | NetherMetals-1.12-1.2.0-rc2.76.jar
orespawn | 3.3.1 | OreSpawn-1.12-3.3.1.172.jar
overpoweredarmorbar | @Version@ | overloadedarmorbar-1.0.4g.jar
psi | r1.1-77 | Psi-r1.1-77.jar
plustic | 7.1.1.2 | plustic-7.1.1.2.jar
potionfingers | r1.0-2 | PotionFingers-r1.0-2.jar
primitivemobs | 1.2.3a | primitivemobs-1.2.3a.jar
quarkoddities | 1 | QuarkOddities-1.12.2.jar
roguelike | 1.8.0 | RoguelikeDungeons-1.12.2-1.8.0.jar
roost | 2.0.10 | roost-1.12.2-2.0.10.jar
scannable | 1.6.3.24 | Scannable-MC1.12.2-1.6.3.24.jar
simpleleather | 1.12-1.0 | simpleleather-1.12-1.0.jar
sky_lanterns | 1.12.1-1.0.1 | skylanterns-1.12.1-1.0.1.jar
solarfurnace | 1.0 | SolarfurnaceMC1.12.2-1.1.jar
storagedrawers | 1.12-5.3.5 | StorageDrawers-1.12.2-5.3.8.jar
storagedrawersextra | @Version@ | StorageDrawersExtras-1.12-3.1.0.jar
tc6aspects4jei | 0.0.2a | tc6aspects4jei-0.0.2a.jar
thaumicjei | 1.6.0 | ThaumicJEI-1.12.2-1.6.0-27.jar
tinkersaddons | 1.0.7 | Tinkers'+Addons-1.12.1-1.0.7.jar
tinkersaether | 1.3.0 | tinkersaether-1.3.0.jar
tcomplement | 1.12.2-0.4.2 | TinkersComplement-1.12.2-0.4.2.jar
tinkersjei | 1.2 | tinkersjei-1.2.jar
tinkertoolleveling | 1.12.2-1.1.0.DEV.b23e769 | TinkerToolLeveling-1.12.2-1.1.0.jar
toughnessbar | 2.1 | toughnessbar-2.3.jar
unifier | 3.0.3 | unifier-3.0.3.jar
uppers | 0.0.6 | Uppers-0.0.6.jar
upsizer | 4.0.1 | upsizer-mc1.12-4.0.1.jar
usefulstuffs | 2.5.7 | UsefulStuffs-1.12.2-2.5.7.jar
vanillafoodpantry | 4.3.1 | vanillafoodpantry-mc1.12.2-4.3.1.jar
wailaharvestability | 1.1.12 | WailaHarvestability-mc1.12-1.1.12.jar
waystones | 4.0.72 | Waystones_1.12.2-4.0.72.jar | None |
wolfarmor | 2.2.3.6 | wolfarmor-1.12.2-2.2.3.1798-universal.jar
woolintostrings | 1.0.2 | WoolIntoStrings-1.12.2-1.0.2.jar
thebetweenlands | 3.4.11 | TheBetweenlands-3.4.11-universal.jar
armoryexpansion-conarm | 1.3.3 | armoryexpansion-1.3.3.jar

Log files
https://pastebin.com/LvxBu71Q

Additional context
This only happens when on the server that I play on. We've tried allowing PowerFist customization in both the client and server config but it still crashes the user.
Works perfectly fine in singleplayer.

Side question, is it possible to make custom cosmetic presets?
(Sorry if this bug report is badly done.)

[DoomRater]

I managed to reproduce in a single player testing world. Not sure what happened here. At first I had the option disabled, then attempted to enable it after getting my hands on a power fist. That world had an editable power fist. But trying on a fresh world with the option pre-enabled, and grabbing one from NEI resulted in the same crash report. I couldn't help but notice the power fist was completely invisible before trying to edit it.

Main difference is my crash does not have tinkers installed. https://pastebin.com/v7PqiDdN

Edit: I think I have a workaround. Create a new power fist with the config set to false. Once you've done that, and you've viewed the item, the NBT stack should be present. Now relog with the edit power fist config set to true, and you should be able to edit it.