Tried to load invalid item Not a boolean: 0, missed input

Expected behavior

An itemstack serialized 1.20.4 should correctly load in 1.21 without errors.

Observed/Actual behavior

on 1.20.4:

Base64.getEncoder().encodeToString(Bukkit.getUnsafe().serializeItem(shulker))

the base64 string: https://0bin.net/paste/gCNq3q2J#fdoLN9dS1PAzhj8eBqeOrnp-xihURktdcDNq1nGLw4a

on 1.21
Bukkit.getUnsafe().deserializeItem(Base64.getDecoder().decode(string));

console error: https://0bin.net/paste/o2chIszJ#52v2olu-s1gmuI/T6IOWtt9OJp3CIgjIu7DgXVqxAyG

The item appears to deserialize correctly, but the console error is still printed, very odd.

Steps/models to reproduce

Encode an item using Bukkit.getUnsafe().serializeItem in 1.20.4

decode said item in 1.21

Plugin and Datapack List

N/A

Paper version

1.21 34a2917

Other

No response

[Warriorrrr]

Pastes have expired and the creator's account has been deleted, closing this as incomplete

[Lulu13022002]

Reopening this one, was a bit discussed internally. Relevant item in the shulker:

1.20.4 item

minecraft:written_book{pages: ['{"extra":[{"color":"gold","text":"Daily Quest Book #188:"},"\\n","\\n",{"extra":[{"underlined":true,"color":"#67CCE0","text":"23h, 55m"}],"text":"This book expires in: "},"\\n",{"color":"gold","text":"Weekly Challenge:"},"\\n","Gain 120 quest points before the end of the week to get: ",{"italic":true,"color":"aqua","hoverEvent":{"action":"show_item","contents":{"id":"minecraft:emerald","tag":"{CustomModelData:1029506977,Enchantments:[{id:\\"minecraft:lure\\",lvl:1s}],HideFlags:1,display:{Lore:[\'{\\"extra\\":[{\\"text\\":\\"Swaps your hotbar\\"}],\\"text\\":\\"\\"}\',\'{\\"extra\\":[{\\"text\\":\\"with the slots above.\\"}],\\"text\\":\\"\\"}\'],Name:\'{\\"extra\\":[{\\"bold\\":false,\\"italic\\":false,\\"underlined\\":false,\\"strikethrough\\":false,\\"obfuscated\\":false,\\"color\\":\\"#26A485\\",\\"text\\":\\"Swap Stone\\"}],\\"text\\":\\"\\"}\'}}"}},"extra":[{"extra":[{"bold":false,"italic":false,"underlined":false,"strikethrough":false,"obfuscated":false,"color":"#26A485","text":"Swap Stone"}],"text":""}],"text":""},"\\n",{"color":"gold","text":"Progress: 9/120"},"\\n",{"bold":true,"color":"#9996FD","extra":[{"bold":true,"color":"#CBCACB","text":"|||||||||||||||||||||||||||||||||||"}],"text":"||"},"\\n",{"extra":[{"underlined":true,"color":"#67CCE0","text":"4D, 0h"}],"text":"Challenge expires in: "}],"text":""}'], display: {Name: '{"extra":[{"bold":false,"italic":false,"underlined":false,"strikethrough":false,"obfuscated":false,"color":"white","text":"Book of Quests"}],"text":""}', Lore: ['{"extra":[{"bold":false,"italic":false,"underlined":false,"strikethrough":false,"obfuscated":false,"color":"white","text":"Its full of quests."}],"text":""}', '{"extra":[{"bold":false,"italic":false,"underlined":false,"strikethrough":false,"obfuscated":false,"color":"gray","text":"Soulbound: Border6"}],"text":""}']}, HideFlags: 32, author: "Border6", title: "Book of Quests"}

Encoded item in base64

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

The lure enchantment is not hidden when migrated for the emerald hover event that happens on the Swap Stone.