Describe the bug
When building a train with over 276 blocks from the list below:

• Copycat Half Layer
• Copycat Box
• Copycat Catwalk
• Copycat Byte
• Copycat Board
  The train disappears when glued together and assembled.

The example of this bug is on the video:
https://youtu.be/gDvIvLrqOM0

As you can see with 276 blocks the train is assembled correctly, but with 277 blocks it disappears when assembled.

To Reproduce
Steps to reproduce the behavior:

1. Start building a train.
2. Put over 276 blocks from the list above.
3. Glue everything together.
4. Press "Assemble the train" and see it disappear.

Expected behavior
Expected the train to not disappear, be visible and interactable.

Desktop (please complete the following information):

• Minecraft 1.20.1
• Forge 47.3.7
• Mod Version: copycats-2.1.2+mc.1.20.1-forge.jar

Additional context
Full list of mods I use:
amendments-1.20-1.2.11.jar
appleskin-forge-mc1.20.1-2.5.1.jar
architectury-9.2.14-forge.jar
balancedflight-1.20.1_v2.3.0.jar
bellsandwhistles-0.4.3-1.20.x.jar
betterarcheology-1.2.1-1.20.1.jar
bobberdetector-0.1.9-1.20.1.jar
Bookshelf-Forge-1.20.1-20.2.13.jar
botarium-forge-1.20.1-2.3.4.jar
carryon-forge-1.20.1-2.1.2.7.jar
cfwinfo-1.2.0.jar
chunkloaders-1.2.8a-forge-mc1.20.1.jar
cloth-config-11.1.118-forge.jar
collective-1.20.1-7.84.jar
constructionwand-1.20.1-2.11.jar
copycats-2.1.2+mc.1.20.1-forge.jar
cornexpansion-forge-1.0.1.jar
create-1.20.1-0.5.1.h.jar
Create-DnDesire-1.20.1-0.1b.Release-Early-Dev.jar
create-dyn-light-forge1.20.1+1.0.1.jar.disabled
create-netherite-jetpack-1.20.1-1.0.3.jar
create-new-age-forge-1.20.1-1.1.2.jar
create-stuff-additions1.20.1_v2.0.4a.jar
createaddition-1.20.1-1.2.4e.jar
createarmoryv0.6.1n.jar
createcontraptionterminals-1.20-1.0.0.jar
createdeco-2.0.2-1.20.1-forge.jar
createdieselgenerators-1.20.1-1.2i.jar
createloveandwar-0.2-1.20.1.jar
createmetallurgy-0.0.5-1.20.1.jar
createmoredrillheads-2.0.3-1.20.1.jar
createoreexcavation-1.20-1.5.2.jar
createstuffadditionsfix-forge-1.20.1-0.0.0.1.jar
createutilities-0.3.0+1.20.1.jar
create_central_kitchen-1.20.1-for-create-0.5.1.f-1.3.12.jar
create_enchantment_industry-1.20.1-for-create-0.5.1.f-1.2.9.d.jar
create_jetpack-forge-4.2.1.jar
create_mechanical_extruder-1.20.1-1.6.1.h-48.jar
create_misc_and_things_ 1.20.1_4.0A.jar
create_villagerology_1.20.1_0c.jar
cristellib-1.1.5-forge.jar
curios-forge-5.10.0+1.20.1.jar
deco-storage-forge-1.20.1-2.0308.jar
decorative_blocks-forge-1.20.1-4.1.3.jar
design_decor-0.4.0b-1.20.1.jar
doaddonfluids-forge-1.3.0.jar
DramaticDoors-QuiFabrge-1.20.1-3.2.5.jar
dummmmmmy-1.20-1.8.19.jar
durabilitytooltip-1.1.5-forge-mc1.20.jar
dynamiclightsreforged-1.20.1_v1.6.0.jar.disabled
embeddium-0.3.31+mc1.20.1.jar
EnchantmentDescriptions-Forge-1.20.1-17.1.18.jar
ExplorersCompass-1.20.1-1.3.3-forge.jar
extendedgears-2.1.1-1.20.1-0.5.1.f-forge.jar
FallingTree-1.20.1-4.3.4.jar
fantasyfurniture-1.20.1-9.0.0.jar
FarmersDelight-1.20.1-1.2.4.jar
flansmod-1.20.1-0.4.193.jar
ForgeConfigScreens-v8.0.2-1.20.1-Forge.jar
formations-1.0.2a-forge-mc1.20.2.jar
formationsnether-1.0.5.jar
formationsoverworld-1.0.4.jar
FramedBlocks-9.3.1.jar
framework-forge-1.20.1-0.7.8.jar
fusion-1.1.1-forge-mc1.20.1.jar
geckolib-forge-1.20.1-4.4.9.jar
guardvillagers-1.20.1-1.6.7.jar
HammerLib-1.20.1-20.1.32.jar
ImprovableSkills-1.20.1-20.1.11.jar
interiors-0.5.4+forge-mc1.20.1.jar
inventorysorter-1.20.1-23.0.1.jar
ironchests-5.0.2-forge.jar
ItemsDisplayedForge-v1.3.0-1.20.1.jar
Jade-1.20.1-forge-11.11.1.jar
jeed-1.20-2.2.2.jar
jei-1.20.1-forge-15.17.0.76.jar
kotlinforforge-4.11.0-all.jar
letsdo-addon-compat-forge-1.4.2.jar
letsdo-API-forge-1.2.15-forge.jar
letsdo-bakery-forge-1.1.15.jar
letsdo-bakery-forge-2.0.2.jar
letsdo-beachparty-forge-1.1.5.jar
letsdo-bloomingnature-forge-1.0.9.jar
letsdo-brewery-forge-1.1.9.jar
letsdo-brewery-forge-2.0.3.jar
letsdo-camping-forge-1.0.3.jar
letsdo-candlelight-forge-1.2.13.jar
letsdo-candlelight-forge-2.0.2.jar
letsdo-farm_and_charm-forge-1.0.3.jar
letsdo-herbalbrews-forge-1.0.8.jar
letsdo-meadow-forge-1.3.19.jar
letsdo-nethervinery-forge-1.2.14.jar
letsdo-vinery-forge-1.4.28.jar
liquidburner-1.20.1-0.5.jar
lmft-1.0.4+1.20.1-forge.jar
mcw-bridges-3.0.0-mc1.20.1forge.jar
mcw-fences-1.1.2-mc1.20.1forge.jar
mcw-furniture-3.3.0-mc1.20.1forge.jar
mcw-holidays-1.1.0-mc1.20.1forge.jar
mcw-lights-1.1.0-mc1.20.1forge.jar
mcw-paths-1.0.5-1.20.1forge.jar
mcw-roofs-2.3.1-mc1.20.1forge.jar
mcw-trapdoors-1.1.3-mc1.20.1forge.jar
mcw-windows-2.3.0-mc1.20.1forge.jar
medieval_seedbags_1.0.1_forge_1.20.1.jar
moonlight-1.20-2.12.17-forge.jar
mysterious_mountain_lib-1.4.7-1.20.1.jar
NaturesCompass-1.20.1-1.11.2-forge.jar
NekosEnchantedBooks-1.20.1-1.8.0.jar
not_interested--mc1.20.1--forge--1.0.jar
oreharvester-1.20.1-1.4.jar
pattern_schematics-1.1.13+forge-1.20.1.jar
petrolpark-1.20.1-1.0.2.jar
petrolsparts-1.20.1-1.0.3.jar
portablemobs-1.2.0-forge-mc1.20.jar
protection_pixel-1.0.5-forge-1.20.1.jar
PuzzlesLib-v8.1.22-1.20.1-Forge.jar
radiantgear-forge-2.1.5+1.20.1.jar
Realistic-Cobwebs-NeoForge-2.1.0-all.jar
rechiseled-1.1.6-forge-mc1.20.jar
rechiseledcreate-1.0.2-forge-mc1.20.jar
refurbished_furniture-forge-1.20.1-1.0.6.jar
resourcefulconfig-forge-1.20.1-2.1.2.jar
resourcefullib-forge-1.20.1-2.1.29.jar
shutter-2.0.5-1.20.1.jar
sight-1.2.2.jar
slavic-delight-0.1-beta.jar
sliceanddice-forge-3.2.1.jar
sophisticatedbackpacks-1.20.1-3.20.6.1064.jar
sophisticatedcore-1.20.1-0.6.25.632.jar
Stackable Potions-forge-1.20.1-1.0.0.jar
Steam_Rails-1.6.5+forge-mc1.20.1.jar
StorageDrawers-1.20.1-12.6.4.jar
StylishEffects-v8.0.2-1.20.1-Forge.jar
supermartijn642configlib-1.1.8-forge-mc1.20.jar
supermartijn642corelib-1.1.17a-forge-mc1.20.1.jar
supersaturation-1.20.1-5.0.0.jar
tinygates-1.20-4.0.0.jar
tinyredstone-1.20-5.0.2.jar
toms_storage-1.20-1.6.8.jar
Towns-and-Towers-1.12-Fabric+Forge.jar
wardrobe-1.0.3.1-forge-1.20.1.jar
XaerosWorldMap_1.39.0_Forge_1.20.jar
Xaeros_Minimap_24.3.0_Forge_1.20.jar
YungsApi-1.20-Forge-4.0.5.jar
YungsBetterDesertTemples-1.20-Forge-3.0.3.jar
YungsBetterDungeons-1.20-Forge-4.0.4.jar
YungsBetterEndIsland-1.20-Forge-2.0.6.jar
YungsBetterJungleTemples-1.20-Forge-2.0.5.jar
YungsBetterMineshafts-1.20-Forge-4.0.4.jar
YungsBetterNetherFortresses-1.20-Forge-2.0.6.jar
YungsBetterOceanMonuments-1.20-Forge-3.0.4.jar
YungsBetterStrongholds-1.20-Forge-4.0.3.jar
YungsBetterWitchHuts-1.20-Forge-3.0.3.jar
YungsBridges-1.20-Forge-4.0.3.jar
YungsExtras-1.20-Forge-4.0.3.jar

I highly suspect that you are hitting the NBT size limit when assembling trains with a lot of copycats. Try increasing that limit in your Create mod config and see if the issue is solved.

Indeed, increasing Max Data Size parameter fixed the issue. Although it's unfortunate that those blocks deplete it so fast.

It is pretty unavoidable since those are multistate copycats which need to store multiple materials and consumed items in each block. I'll close this issue since there's not much we can do.