Title says it all, can confirm there is essentia flowing through them, checked with the essentia resonator, but i can't see it flowing through the tubes like your supposed to.

Do you have anything like OptiFine installed? If you do it might mess with the rendering of essentia in tubes.

A screenshot might help. While I don't know all of the available renders that might be visible in the scene, I've seen all sorts of wonky things before including invisible enemies blocking out the face of zombies, and a lot of the times it's just the way OpenGL is told to render things. A screenshot might be able to tell us whether it's a problem on a mod's end, or conflicting renders.

I did at one point, but not currently

Can I have your mod list? I saw this happen once in testing, but it was also while I was messing with the glass tube renderer so I thought I just messed up. Going to a new world after restarting the game also fixed it, so that leads me to think a mod is doing some weird rendering.

Can I have your mod list? I saw this happen once in testing, but it was also while I was messing with the glass tube renderer so I thought I just messed up. Going to a new world after restarting the game also fixed it, so that leads me to think a mod is doing some weird rendering.

Lucraft: Core - Lucraft - LucraftCore-1.12.2-2.4.13.jar
Planar Artifice Unofficial - Zokonius - planarartifice-1.0.0.jar
AcademyCraft - weathfold - AcademyCraft-1.1.3.jar
Actually Additions - Ellpeck - ActuallyAdditions-1.12.2-r152.jar
Additional Structures - XxRexRaptorxX - Rex's-Additional-Structures-1.12.x-(v.2.3.1).jar
Anvil Infinity Craft - AnvilcraftMC - infinity-1.12.jar
Arcanum - xHellBreecher - arcanum-1.12.2-4.3.0.0.jar
Astral Additions - ArcAios26 - astraladditions-1.12.2-1.0.0.jar
Astral Sorcery - HellFirePvP - astralsorcery-1.12.2-1.10.27.jar
AutoRegLib - Vazkii - AutoRegLib-1.3-32.jar
Avaritia 1.1x - brandon3055 - Avaritia-1.12.2-3.3.0.37-universal.jar
Avaritia's Complement - tfarecnim - Avaritia's Complement-1.12.2-1.4.jar
Avaritiaddons - WanionCane - Avaritiaddons-1.12.2-1.2.jar
Baubles - Azanor13 - Baubles-1.12-1.5.2.jar
Bewitchment (Legacy) - sunconure11 - bewitchment-1.12.2-0.0.22.64.jar
BiblioCraft - Nuchaz - BiblioCraft[v2.4.5][MC1.12.2].jar
Block Drops (JEI Addon) - KidsDontPlay - blockdrops-1.12.2-1.4.0.jar
Blood Magic - WayofTime - BloodMagic-1.12.2-2.4.3-105.jar
Botania - Vazkii - Botania r1.10-364.4.jar
Brandon's Core - brandon3055 - BrandonsCore-1.12.2-2.4.19.214-universal.jar
Building Gadgets - Direwolf20 - BuildingGadgets-2.8.4.jar
CB Multipart - covers1624 - ForgeMultipart-1.12.2-2.6.2.83-universal.jar
Chicken Chunks 1.8.+ - covers1624 - ChickenChunks-1.12.2-2.4.2.74-universal.jar
Chisel - tterrag1098 - Chisel-MC1.12.2-1.0.2.45.jar
Chisels & Bits - AlgorithmX2 - chiselsandbits-14.33.jar
CodeChicken Lib 1.8.+ - covers1624 - CodeChickenLib-1.12.2-3.2.3.358-universal.jar
CoFH Core - TeamCoFH - CoFHCore-1.12.2-4.6.6.1-universal.jar
CoFH World - TeamCoFH - CoFHWorld-1.12.2-1.4.0.1-universal.jar
ConnectedTexturesMod - tterrag1098 - CTM-MC1.12.2-1.0.2.31.jar
Cosmetic Armor Reworked - LainMI - CosmeticArmorReworked-1.12.2-v5a.jar
Crimson Revelations - mobiusflip - crimsonrevelations-0.8.jar
Cucumber Library - BlakeBr0 - Cucumber-1.12.2-1.1.3.jar
Cyclops Core - kroeser - CyclopsCore-1.12.2-1.6.7.jar
DimensionalDoors - DimensionalDevelopment - DimensionalDoors-1.12.2-3.1.2-UNOFFICIAL.jar
Doctor Who - Regeneration - Suff99 - Regeneration-1.12.2-3.0.2.jar
Draconic Evolution - brandon3055 - Draconic-Evolution-1.12.2-2.3.27.353-universal.jar
DummyCore Unofficial - TheLMiffy1111 - DummyCoreUnofficial-2.4.112.5.jar
Ender IO - idontwantthisaccount4 - EnderIO-1.12.2-5.3.70.jar
EnderCore - tterrag1098 - EnderCore-1.12.2-0.5.76.jar
EvilCraft - kroeser - EvilCraft-1.12.2-0.10.78.jar
Expanded Arcanum - mallrat208 - ExpandedArcanum-1.0.1.jar
Extra Utilities - Forge_User_06804776 - extrautils2-1.12-1.9.9.jar
Fancy Lamps - a_frosted_one - fancylamps-1.2.1.jar
Forbidden and Arcanus - cesar_zorak - forbidden_arcanus-1.12.2-1.1.4.jar
Guide-API - TehNut - Guide-API-1.12-2.1.8-63.jar
Hammer (Lib) Core - Zeitheron - HammerLib-1.12.2-2.0.6.26.jar
HeroesExpansion - Lucraft - HeroesExpansion-1.12.2-1.3.5.jar
Hwyla - TehNut - Hwyla-1.8.26-B41_1.12.2.jar
IBE Editor - Franckyi - IBEEditor-1.12.2-1.0.0-alpha5.jar
Ice and Fire: Dragons - alex1the1666 - iceandfire-1.9.1-1.12.2.jar
Immersive Engineering - BluSunrize - ImmersiveEngineering-0.12-98.jar
IronMan - Lucraft - IronMan-1.12.2-Beta-1.12.2-1.2.6.jar
JEI Integration - SnowShock35 - jeiintegration_1.12.2-1.6.0.jar
JEI Villagers - Buuz135 - jeivillagers-1.12-1.0.2.jar
JourneyMap - techbrew - journeymap-1.12.2-5.7.1.jar
Just Enough Items (JEI) - mezz - jei_1.12.2-4.16.1.301.jar
Just Enough Resources (JER) - way2muchnoise - JustEnoughResources-1.12.2-0.9.2.60.jar
JustEnoughIDs - Runemoro - JustEnoughIDs-1.0.3-55.jar
LibrarianLib - wiresegal - librarianlib-1.12.2-4.22.jar
Librikka API - rikka0w0 - librikka-1.0.0.jar
LLibrary - _ForgeUser11902522 - llibrary-1.7.20-1.12.2.jar
Lost Magic - Spiteful_Fox - lostmagic-1.0.2.jar
LunatriusCore - Lunatrius - LunatriusCore-1.12.2-1.2.0.42-universal.jar
Magic Arsenal - falkreon - MagicArsenal-MC1.12_ver1.2.5.jar
MagicalSculpture - yuriscat - magicalsculpture-1.0.0.jar
Mahou Tsukai - stepcros - mahoutsukai-1.12.2-v1.19.46.jar
Mantle - mDiyo - Mantle-1.12-1.3.3.55.jar
MrCrayfish's Furniture Mod - MrCrayfish - furniture-6.3.1-1.12.2.jar
MrTJPCore - MrTJP - MrTJPCore-1.12.2-2.1.4.43-universal.jar
Mystical Agriculture - BlakeBr0 - MysticalAgriculture-1.12.2-1.7.5.jar
Not Enough Items 1.8.+ - covers1624 - NotEnoughItems-1.12.2-2.4.3.245-universal.jar
Patchouli - Vazkii - Patchouli-1.0-23.6.jar
Project Red - Compat - MrTJP - ProjectRed-1.12.2-4.9.4.120-compat.jar
Project Red - Core - MrTJP - ProjectRed-1.12.2-4.9.4.120-Base.jar
Project Red - Expansion - MrTJP - ProjectRed-1.12.2-4.9.4.120-mechanical.jar
Project Red - Illumination - MrTJP - ProjectRed-1.12.2-4.9.4.120-lighting.jar
Project Red - Integration - MrTJP - ProjectRed-1.12.2-4.9.4.120-integration.jar
Psi - Vazkii - Psi-r1.1-78.2.jar
Psionic Peripherals - Dudblockman - psipherals-1.1.0.jar
PymTech - Lucraft - PymTech-1.12.2-1.0.2.jar
Quark - Vazkii - Quark-r1.6-179.jar
Random PSIdeas - kamefrede123 - rpsideas-2.4.4.jar
Random Things - Lumien231 - RandomThings-MC1.12.2-4.2.7.4.jar
Redstone Flux - TeamCoFH - RedstoneFlux-1.12-2.1.1.1-universal.jar
Reliquary v1.3 - P3pp3rF1y - Reliquary-1.12.2-1.3.4.796.jar
Schematica - Lunatrius - Schematica-1.12.2-1.8.0.169-universal.jar
Shadowfacts' Forgelin - ShadowfactsDev - Forgelin-1.8.4.jar
Speedster Heroes - Lucraft - SpeedsterHeroes-1.12.2-2.2.1.jar
Structures Orb - spraxsuper - structures orbs [update 1!].jar
Thaumcraft - Azanor13 - Thaumcraft-1.12.2-6.1.BETA26.jar
Thaumcraft 6 Aspects for JEI - zabi94 - tc6aspects4jei-0.0.2a.jar
Thaumic Additions: Reconstructed - Zeitheron - ThaumicAdditions-1.12.2-12.6.7.jar
Thaumic Arcana - thefrontrider - Thaumic Arcana-1.3.0.jar
Thaumic Augmentation - TheCodex6824 - ThaumicAugmentation-1.12.2-2.1.1.jar
Thaumic Bases Unofficial - Rumaruka - thaumicbases-3.3.500.6r.jar
Thaumic Brewing - daedalus4096 - thaumicbrewing-1.0.2.jar
Thaumic Gadgets - ArcAnc - Thaumic_Gadgets_1.12.2_0.1.6_tb.26.jar
Thaumic Inventory Scanning (Thaumcraft Addon) - BlayTheNinth - ThaumicInventoryScanning_1.12.2-2.0.10.jar
Thaumic JEI - Buuz135 - ThaumicJEI-1.12.2-1.6.0-27.jar
Thaumic Periphery - cadaverous_queen - thaumicperiphery-0.3.1.jar
Thaumic Restoration - Zokonius - ThaumicRestoration-1.5.0.jar
Thaumic Tinkerer - gaeakat - thaumictinkerer-1.12.2-5.0-620a0c5.jar
Thaumic Wonders - daedalus4096 - thaumicwonders-1.8.2.jar
The Aether II - GildedGames - aether_ii-1.12.2-0.3.0+build411-universal.jar
The Twilight Forest - Benimatic - twilightforest-1.12.2-3.11.1021-universal.jar
Tinkering with Blood Magic - terrapin47 - bloodtinker-1.0.5.jar
Tinkers Construct - mDiyo - TConstruct-1.12.2-2.13.0.183.jar
WanionLib - WanionCane - WanionLib-1.12.2-2.5.jar
Wawla - What Are We Looking At - DarkhaxDev - Wawla-1.12.2-2.6.275.jar
Waystones - BlayTheNinth - Waystones_1.12.2-4.1.0.jar

Hi! I have the same problem but I have different modlist. I will post here all mods I have in common with CaptainShadow5:

Planar Artifice Unofficial - Zokonius - planarartifice-1.0.0.jar
Baubles - Azanor13 - Baubles-1.12-1.5.2.jar
BiblioCraft - Nuchaz - BiblioCraft[v2.4.5][MC1.12.2].jar
Block Drops (JEI Addon) - KidsDontPlay - blockdrops-1.12.2-1.4.0.jar
Chisel - tterrag1098 - Chisel-MC1.12.2-1.0.2.45.jar
Chisels & Bits - AlgorithmX2 - chiselsandbits-14.33.jar
CodeChicken Lib 1.8.+ - covers1624 - CodeChickenLib-1.12.2-3.2.3.358-universal.jar
ConnectedTexturesMod - tterrag1098 - CTM-MC1.12.2-1.0.2.31.jar
Cosmetic Armor Reworked - LainMI - CosmeticArmorReworked-1.12.2-v5a.jar
Cucumber Library - BlakeBr0 - Cucumber-1.12.2-1.1.3.jar
DummyCore Unofficial - TheLMiffy1111 - DummyCoreUnofficial-2.4.112.5.jar
Expanded Arcanum - mallrat208 - ExpandedArcanum-1.0.1.jar
Fancy Lamps - a_frosted_one - fancylamps-1.2.1.jar
Guide-API - TehNut - Guide-API-1.12-2.1.8-63.jar
Hammer (Lib) Core - Zeitheron - HammerLib-1.12.2-2.0.6.26.jar
Hwyla - TehNut - Hwyla-1.8.26-B41_1.12.2.jar
JEI Integration - SnowShock35 - jeiintegration_1.12.2-1.6.0.jar
JEI Villagers - Buuz135 - jeivillagers-1.12-1.0.2.jar
JourneyMap - techbrew - journeymap-1.12.2-5.7.1.jar
Just Enough Items (JEI) - mezz - jei_1.12.2-4.16.1.301.jar
Just Enough Resources (JER) - way2muchnoise - JustEnoughResources-1.12.2-0.9.2.60.jar
LunatriusCore - Lunatrius - LunatriusCore-1.12.2-1.2.0.42-universal.jar
Mantle - mDiyo - Mantle-1.12-1.3.3.55.jar
Mystical Agriculture - BlakeBr0 - MysticalAgriculture-1.12.2-1.7.5.jar
Patchouli - Vazkii - Patchouli-1.0-23.6.jar
Schematica - Lunatrius - Schematica-1.12.2-1.8.0.169-universal.jar
Thaumcraft - Azanor13 - Thaumcraft-1.12.2-6.1.BETA26.jar
Thaumic Additions: Reconstructed - Zeitheron - ThaumicAdditions-1.12.2-12.6.7.jar
Thaumic Arcana - thefrontrider - Thaumic Arcana-1.3.0.jar
Thaumic Augmentation - TheCodex6824 - ThaumicAugmentation-1.12.2-2.1.1.jar
Thaumic Bases Unofficial - Rumaruka - thaumicbases-3.3.500.6r.jar
Thaumic Gadgets - ArcAnc - Thaumic_Gadgets_1.12.2_0.1.6_tb.26.jar
Thaumic Inventory Scanning (Thaumcraft Addon) - BlayTheNinth - ThaumicInventoryScanning_1.12.2-2.0.10.jar
Thaumic JEI - Buuz135 - ThaumicJEI-1.12.2-1.6.0-27.jar
Thaumic Periphery - cadaverous_queen - thaumicperiphery-0.3.1.jar
Thaumic Restoration - Zokonius - ThaumicRestoration-1.5.0.jar
Thaumic Tinkerer - gaeakat - thaumictinkerer-1.12.2-5.0-620a0c5.jar
Thaumic Wonders - daedalus4096 - thaumicwonders-1.8.2.jar
The Twilight Forest - Benimatic - twilightforest-1.12.2-3.11.1021-universal.jar
Wawla - What Are We Looking At - DarkhaxDev - Wawla-1.12.2-2.6.275.jar

I hope this helps you identify the problem.

PS: I'll try to reduce this list by removing some of them :)

Edit: for some reason I do not understand, all my tubes now show essentia inside, as long as this is how its suposed to look like:

Mine are also working, the only thing that's changed is a windows update.

Yeah this was a tricky one, turns out that certain blocks change something related to rendering and then don't set it back when they're done. It's so inconsistent because you need to have one of these blocks render to have the essentia become invisible. But it should be fixed for the next update.