The bug
If a written book in a 1.20.2 world contains JSON text that is invalid as of 1.20.3, the book will stop working after the world is upgraded. This only affects unread books (that is, books without the resolved tag set to true).
How to reproduce
In Version 1.20.2, give yourself two identical written books as follows:
/give @s written_book{pages:['{"text":"Sample text","color":"zzz"}'],title:MC-269335,author:j_p_smith} 2Place the books in separate slots
Open one of the books
Save the world and open it in the latest version/snapshot
Open the same book as before
→ ✔ This book displays its text correctlyOpen the other book
→ ❌ This book displays raw JSON text (1.20.4) or is blank (24w10a)
Thank you for your report!
After consideration, the issue is being closed as Working as Intended.
Please note, that mechanics of the game may change between updates.
Things such as graphics, sounds, world creation, biomes, redstone, villagers, and animals may not work the same in current versions.
Full Version History – Snapshot Version History – The official Minecraft feedback site
Quick Links:
📓 Bug Tracker Guidelines – 💬 Community Support – 📧 Mojang Support (Technical Issues) – 📧 Microsoft Support (Account Issues)
📓 Project Summary – ✍️ Feedback and Suggestions – 📖 Game Wiki