Describe the bug
When I right-click on the backpack to add it to my back, I don't see the option to equip/unequip option in the GUI.
I had curios integration turned off.

To Reproduce
Steps to reproduce the behavior:

1. Hold backpack in hand
2. Right-click to show GUI
3. GUI does not have option to equip/unequip

Expected behavior
I expect to see the equip/unequip option when I right-click the backpack in hand.

Screenshots
If applicable, add screenshots to help explain your problem.

Required informations (please complete the following information):

• Mod version: 1.16.5 - 5.4.0]\
• Forge 36.1
• Minecraft 1.16.5

Additional context
Add any other context about the problem here.

No more responds, closing

Yes it is still occuring. Here are a list of my mods:

Mods:
[✔️] 1.16.5-additionalbars-2.0.2
[✔️] abnormals_core-1.16.5-3.1.1
[✔️] abnormals_delight-1.16.5-1.1.0
[✔️] additionalbarsbop-2.0.2
[✔️] AdvancedCompas-forge-1.16.5-1.0.0
[✔️] alexsmobs-1.8.1
[✔️] architectury-1.10.139-forge
[✔️] Artifacts-1.16.5-2.8.3
[✔️] astikorcarts-1.16.5-1.1.1
[✔️] atmospheric-1.16.5-3.1.0
[✔️] AttributeFix-1.16.5-10.1.2
[✔️] autoplant-1.16.5-1.0.0
[✔️] AutoRegLib-1.6-47
[✔️] autumnity-1.16.5-2.1.0
[✔️] bambooeverything-1.16.3-forge-1.0.0
[✔️] Bayou-Blues-1.16.5-1.0.4
[✔️] BedBenefits-1.16.5-5.0.3
[✔️] berry_good-1.16.5-4.1.1
[✔️] better_respawn-1.16.5-1.0.1
[✔️] BetterAdvancements-1.16.5-0.1.0.105
[✔️] Better-Badlands-1.16.5-2.0.3
[✔️] BetterBurning-1.16.5-6.0.3
[✔️] BetterCaves-Forge-1.16.4-1.1.1
[✔️] betterendforge-1.16.4-1.5.1
[✔️] BetterF3-1.1.2-forge-1.16.4
[✔️] BetterMineshafts-Forge-1.16.4-2.0.3
[✔️] BetterShieldsMC1.16.3-1.1.4
[✔️] betterspawnercontrol_1.16.5-1.3
[✔️] biomeinfo-1.16.4-v1.3
[✔️] BiomesOPlenty-1.16.4-13.0.0.432-universal
[✔️] blame-1.16.4-1.9.2
[✔️] Bookshelf-1.16.5-10.0.7
[✔️] Bountiful-1.16.4-3.3.1
[✔️] caelus-forge-1.16.5-2.1.3.0
[✔️] campfiretorches-1.16.3-1.0.3
[✔️] campful-1.16.5-3.1.0
[✔️] cartographer-0.0.2-1.16.5-36.0.52
[✔️] charm-forge-1.16.5-2.3.2
[✔️] chocolate-1.3.0-1.16.4
[✔️] ChunkAnimator-1.16.5-1.2.3
[✔️] citadel-1.6.2
[✔️] cloth-config-4.11.18-forge
[✔️] Clumps-6.0.0.17
[✔️] CNB-1.16.3_5-1.2.11
[✔️] collective-1.16.5-2.25
[✔️] colytra-forge-1.16.4-5.1.0.0
[✔️] comforts-forge-1.16.4-4.0.1.0
[✔️] configured-0.3.0-1.16.3
[✔️] corpse-1.16.5-1.0.2
[✔️] create-mc1.16.5_v0.3.1a
[✔️] cuneiform-1.16.3-1.2.3.1
[✔️] curios-forge-1.16.5-4.0.5.0
[✔️] deadlyendphantoms-1.16.4-3.0.0
[✔️] Desolation 1.0.5b 1.16.5
[✔️] despawningeggshatch_1.16.5-2.2
[✔️] dismountentity_1.16.5-1.4
[✔️] DungeonCrawl-1.16.3-2.2.4
[✔️] dungeons_plus-1.16.4-1.1.3
[✔️] DynamicSurroundings-1.16.4-4.0.4.1
[✔️] EasyMagic-v1.0.2-1.16.5
[✔️] endergetic-1.16.4-3.0.0
[✔️] enhancedcelestials-1.0.2-1.16.4
[✔️] Enhanced-Mushrooms-1.16.5-3.0.7
[✔️] entityculling-1.2.1
[✔️] environmental-1.16.5-1.0.0
[✔️] extendedbonemeal_1.16.5-1.3
[✔️] extraboats-1.16.5-2.1.0
[✔️] extratrades-1.16.4-1.1
[✔️] FallingTree-Forge-1.16.5-2.11.0
[✔️] fancymenu_2.0.6_MC_1.16.2-1.16.5
[✔️] FarmersDelight-1.16.3-0.3.2
[✔️] farmersdelightintegration-1.16.5-1.0.3
[✔️] farmersdelightintegrations-1.16.5-1.1
[✔️] FastLeafDecay-v25
[✔️] FpsReducer-mc1.16.4-1.18
[✔️] geckolib-forge-1.16.5-3.0.19
[✔️] goblintraders-1.3.1-1.16.3
[✔️] guardvillagers-1.16.5.1.2.2
[✔️] HerdMentality-1.16.5-6.0.2
[✔️] hunterillager-1.16.4-1.2.2
[✔️] illagers_plus-1.16.4v1.0
[✔️] illagersweararmor-1.0.4
[✔️] infernal-expansion-forge-1.3
[✔️] InventoryHud_[1.16.2-1.16.5].forge-3.2.2
[✔️] inventorytotem_1.16.5-1.3
[✔️] Jade-1.16.4-2.6.1
[✔️] jei-1.16.5-7.6.1.75
[✔️] jeiintegration_1.16.5-7.0.1.15
[✔️] Kiwi-1.16.5-3.4.2
[✔️] konkrete_1.1.5_MC_1.16.2-1.16.5
[✔️] kotlinforforge-1.11.0-obf
[✔️] kubejs-1605.3.6-build.178-forge
[✔️] LetSleepingDogsLie-1.16.3-1.1.1
[✔️] LurkerMod(FORGE-1.16.4) - 1.0.8
[✔️] masonry-1.16.3-0.3.6
[✔️] mcw-bridges-1.0.5-mc1.16.5-4
[✔️] mcw-doors-1.0.2-mc1.16.5
[✔️] mcw-fences-1.0.0-mc1.16.5
[✔️] mcw-furniture-2.0.1-mc1.16.5
[✔️] mcw-roofs-2.0.1-mc1.16.5-4
[✔️] mcw-trapdors-1.0.1-mc1.16.5
[✔️] mcw-windows-1.0.3-mc1.16.5
[✔️] MoreCraftingTables - 1.16.5
[✔️] morezombievillagers_1.16.5-1.3
[✔️] movingelevators-1.2.33-mc1.16.5
[✔️] NetherPortalFix_1.16.3-7.2.1
[✔️] netherportalspread_1.16.5-5.1
[✔️] netherskeletons
[✔️] oneplayersleeping-1.16.4-0.0.5
[✔️] OuterEnd-0.2.8
[✔️] outvoted-1.16.5-1.2.2
[✔️] overloadedarmorbar-5.1.0
[✔️] passiveshield_1.16.5-1.3
[✔️] pathundergates-1.16.4-2.0.0-release
[✔️] PickUpNotifier-v1.2-1.16.3
[✔️] Pillagers-1.16.5-3.0.1
[✔️] plaingrinder-1.16.5-1.0.0
[✔️] polymorph-forge-1.16.5-0.24
[✔️] pop-1.16.5-1.0.0
[✔️] preview_OptiFine_1.16.5_HD_U_G8_pre11
[✔️] QuarkOPlenty-1.16.5-1.2.1
[✔️] Quark-r2.4-309
[✔️] randompatches-2.4.4-forge
[✔️] Regrowth-1.16.4-1.16.4-1.35.0.18
[✔️] repurposed_structures-1.16.5-2.5.1
[✔️] RevampedWolf-1.16.4-0.7.1
[✔️] rhino-1.7.13-build.14
[✔️] savageandravage-1.16.5-3.1.0
[✔️] SaveMyStronghold-1.16.4-1.0
[✔️] SereneSeasons-1.16.5-4.0.1.91-universal
[✔️] smoothboot-forge-1.16.4-1.2.2
[✔️] SpawnBalanceUtility-1.36.0.5
[✔️] stoneholm-1.1
[✔️] strayspawn_1.16.5-1.3
[✔️] structure_gel-1.16.4-1.7.5
[✔️] SubWild-1.16.5-1.2.0
[✔️] supplementaries-1.16.5-0.11.0b
[✔️] swingthroughgrass-1.16.4-1.5.3
[✔️] TenshiLib-1.16.3-1.3.0
[✔️] Tips-1.16.5-4.0.8
[✔️] ToolBelt-1.16.5-1.16.0
[✔️] totaldarkness-1.2-1.16.3
[✔️] toughnessbar-6.1
[✔️] TrashSlot_1.16.3-12.2.1
[✔️] travelers_index-1.16.4-1.0.2
[✔️] TravelersBackpack-1.16.5-5.4.0
[✔️] u_team_core-1.16.5-3.2.0.194
[✔️] upgrade_aquatic-1.16.5-3.1.0
[✔️] Upgraded Netherite 1.16.4 - 1.8.1
[✔️] upstream-1.0
[✔️] Variant16x-1.16.5-v0.17.4.5_beta
[✔️] Variant16x-BiomesOPlenty-1.16.5-v0.17.4.4_beta
[✔️] villagernames_1.16.5-2.9
[✔️] Waystones_1.16.5-7.4.0
[✔️] WitherBones2.0.1-MC1.16.4
[✔️] xlpackets-1.1
[✔️] YungsApi-1.16.4-Forge-4

There's still a problem? I don't see anyone else reporting this issue

Is there a way you could send me your modpack via Discord or something?

Or did the issue resolve?

Sorry, I have been busy with RL. No, it is still happening. I'll try to see if there is a mod conflict...

I had the same problem when I had multiple bags - it turned out that I was wearing one already. I pressed 'b', then removed the equipped bag, then opened my 'main' bag in my hand, then equipped the bag I wanted.

I'm sure you checked this but, just in case,

I thought it was maybe because I had curios installed at first, but I disabled it and the option in the config...same thing.
I am going to give it another go, RL has gotten in the way of me looking into this further.

If you wear backpack there should be tank icons in right bottom corner. Then use keybind to open backpack (Default B), mods may cause conflicts, so make sure you checked it's okay to use this keybind. Also if you already wear a backpack, equip/unequip button won't appear, unless it's worn backpack's gui.
There might be bug too though, try /kill, maybe backpack is stuck somehow