Builder has issues placing chiseled bookcases containing 3 books

Is there an existing issue for this?

• I have searched the existing issues.

Are you using the latest Structurize Version?

• I am running the latest beta/release version of Structurize for my Minecraft version.
  I am also running the latest versions of other mods that are part of my problem.

Did you check on the Wiki? or ask on Discord?

• I checked the MineColonies/Structurize Wiki or I asked on discord.

Minecraft Version

1.21

Structurize Version

833

MineColonies Version (if related bug)

1381

Related Mods and their Versions

DO version 236

Current Behavior

The schematic has this bookcase.

When the builder gets to it, and there is a chiseled bookcase and 3 books in the hut racks, they get confused and lock up. They stop working. They're not sick, mourning, hungry, on leisure; it is day with no rain. After several days, I took it all from them, placed it per schematic, and canceled their request for a new bookcase (which appeared because I'd taken it from them), and paused/restarted them several times, and they proceeded with the rest of the build.

As a note: I playtested this build several times earlier this year, without any issues, so I suspect a change must have broken this handling at some point.

Expected Behavior

Place all vanilla blocks successfully with appropriate contents, per schematic.

Reproduction Steps

Place a schematic for builder (Archwood Collective builder hut). Do not touch mirror control. (I may have rotated, I do not recall).
Allow them to build level 1, then upgrade to level 2 (the problem block in this build is in level 2)
Observe error

build request timestamp in logs I believe is 14Sep2026 13:50:23.290

Logs

https://gist.github.com/Shadizar/59878d563fe20522ca2c69cf30f36c60

Anything else?

No response

Footer

---

Viewers

• Add a thumbs-up to the bug report if you are also affected. This helps the bug report become more visible to the team and doesn't clutter the comments.
• Add a comment if you have any insights or background information that isn't already part of the conversation.

Reproduce the Archwood Collective builder hut upgrade with the chiseled bookcase containing three books, then inspect the linked log around the reported build request. Trace the builder's handling of vanilla blocks with contents; done means the level 2 build places the bookcase and books successfully without the builder locking up.