Structurize crash when rotating decoration

[Shadizar]

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

1.0.802

MineColonies Version (if related bug)

1.1.1242

Related Mods and their Versions

Blockui 1.0.208
Neoforge 21.1.217
Biomes O Plenty 21.1.0.13 (note, BoP items are not used in the exact schematic that is crashing, but the style requires this mod, or it will be hidden)
Ars Nouveau 5.11.1
Archwood Collective stylepack from https://www.planetminecraft.com/project/archwood-collective-minecolonies-style-1-21/ (version is 19)

Current Behavior

Crash when rotating decoration schematic.

Expected Behavior

No crash.

Reproduction Steps

1. Create a colony.
2. Ensure you have a functioning builder (probably not needed for the repro)
3. Ensure you have Archwood Collective 1.21.1 style installed. This requires BoP and Ars nouveau. Versions of those mods are listed in related mods.
4. Using build tool (I was in creative), inside the colony, bring up preview of decorations/sourcegeneration/berryburntile.
5. Rotate (or mirror, according to another user). I did it with the keystrokes, I assume it'll bug for any rotation.
6. Crash

Logs

https://gist.github.com/Shadizar/296959ac2078d51565f8676734fdc4fa

Anything else?

[21Jan2026 17:34:04.816] [Render thread/ERROR] [net.minecraft.client.Minecraft/FATAL]: Reported exception thrown!
net.minecraft.ReportedException: KeyPressed event for BO screen
at TRANSFORMER/minecraft@1.21.1/net.minecraft.client.gui.screens.Screen.wrapScreenError(Screen.java:456) ~[client-1.21.1-20240808.144430-srg.jar%23618!/:?]
at TRANSFORMER/minecraft@1.21.1/net.minecraft.client.KeyboardHandler.keyPress(KeyboardHandler.java:407) ~[client-1.21.1-20240808.144430-srg.jar%23618!/:?]
at TRANSFORMER/minecraft@1.21.1/net.minecraft.client.KeyboardHandler.lambda$setup$8(KeyboardHandler.java:515) ~[client-1.21.1-20240808.144430-srg.jar%23618!/:?]
at TRANSFORMER/minecraft@1.21.1/net.minecraft.util.thread.BlockableEventLoop.execute(BlockableEventLoop.java:98) ~[client-1.21.1-20240808.144430-srg.jar%23618!/:?]
at TRANSFORMER/minecraft@1.21.1/net.minecraft.client.KeyboardHandler.lambda$setup$9(KeyboardHandler.java:515) ~[client-1.21.1-20240808.144430-srg.jar%23618!/:?]
at MC-BOOTSTRAP/org.lwjgl.glfw@3.3.3+5/org.lwjgl.glfw.GLFWKeyCallbackI.callback(GLFWKeyCallbackI.java:44) ~[lwjgl-glfw-3.3.3.jar%23173!/:build 5]
at MC-BOOTSTRAP/org.lwjgl@3.3.3+5/org.lwjgl.system.JNI.invokeV(Native Method) ~[lwjgl-3.3.3.jar%23185!/:build 5]
at MC-BOOTSTRAP/org.lwjgl.glfw@3.3.3+5/org.lwjgl.glfw.GLFW.glfwWaitEventsTimeout(GLFW.java:3509) ~[lwjgl-glfw-3.3.3.jar%23173!/:build 5]
at TRANSFORMER/minecraft@1.21.1/com.mojang.blaze3d.systems.RenderSystem.limitDisplayFPS(RenderSystem.java:162) ~[client-1.21.1-20240808.144430-srg.jar%23618!/:?]
at TRANSFORMER/minecraft@1.21.1/net.minecraft.client.Minecraft.runTick(Minecraft.java:1220) ~[client-1.21.1-20240808.144430-srg.jar%23618!/:?]
at TRANSFORMER/minecraft@1.21.1/net.minecraft.client.Minecraft.run(Minecraft.java:807) ~[client-1.21.1-20240808.144430-srg.jar%23618!/:?]
at TRANSFORMER/minecraft@1.21.1/net.minecraft.client.main.Main.main(Main.java:230) ~[client-1.21.1-20240808.144430-srg.jar%23618!/:?]
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[?:?]
at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[?:?]
at MC-BOOTSTRAP/fml_loader@4.0.42/net.neoforged.fml.loading.targets.CommonLaunchHandler.runTarget(CommonLaunchHandler.java:136) ~[loader-4.0.42.jar%23107!/:4.0]
at MC-BOOTSTRAP/fml_loader@4.0.42/net.neoforged.fml.loading.targets.CommonLaunchHandler.clientService(CommonLaunchHandler.java:124) ~[loader-4.0.42.jar%23107!/:4.0]
at MC-BOOTSTRAP/fml_loader@4.0.42/net.neoforged.fml.loading.targets.CommonClientLaunchHandler.runService(CommonClientLaunchHandler.java:32) ~[loader-4.0.42.jar%23107!/:4.0]
at MC-BOOTSTRAP/fml_loader@4.0.42/net.neoforged.fml.loading.targets.CommonLaunchHandler.lambda$launchService$4(CommonLaunchHandler.java:118) ~[loader-4.0.42.jar%23107!/:4.0]
at MC-BOOTSTRAP/cpw.mods.modlauncher@11.0.5/cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:30) [modlauncher-11.0.5.jar%23112!/:?]
at MC-BOOTSTRAP/cpw.mods.modlauncher@11.0.5/cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:53) [modlauncher-11.0.5.jar%23112!/:?]
at MC-BOOTSTRAP/cpw.mods.modlauncher@11.0.5/cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:71) [modlauncher-11.0.5.jar%23112!/:?]
at MC-BOOTSTRAP/cpw.mods.modlauncher@11.0.5/cpw.mods.modlauncher.Launcher.run(Launcher.java:103) [modlauncher-11.0.5.jar%23112!/:?]
at MC-BOOTSTRAP/cpw.mods.modlauncher@11.0.5/cpw.mods.modlauncher.Launcher.main(Launcher.java:74) [modlauncher-11.0.5.jar%23112!/:?]
at MC-BOOTSTRAP/cpw.mods.modlauncher@11.0.5/cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:26) [modlauncher-11.0.5.jar%23112!/:?]
at MC-BOOTSTRAP/cpw.mods.modlauncher@11.0.5/cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:23) [modlauncher-11.0.5.jar%23112!/:?]
at cpw.mods.bootstraplauncher@2.0.2/cpw.mods.bootstraplauncher.BootstrapLauncher.run(BootstrapLauncher.java:210) [bootstraplauncher-2.0.2.jar:?]
at cpw.mods.bootstraplauncher@2.0.2/cpw.mods.bootstraplauncher.BootstrapLauncher.main(BootstrapLauncher.java:69) [bootstraplauncher-2.0.2.jar:?]
Caused by: java.lang.ArrayIndexOutOfBoundsException: Index 2 out of bounds for length 2
at TRANSFORMER/structurize@1.0.802-1.21.1-snapshot/com.ldtteam.structurize.component.CapturedBlock.applyRotationMirror(CapturedBlock.java:81) ~[structurize-1.0.802-1.21.1-snapshot.jar%23989!/:1.0.802-1.21.1-snapshot]
at TRANSFORMER/structurize@1.0.802-1.21.1-snapshot/com.ldtteam.structurize.blueprints.v1.Blueprint.setRotationMirrorRelative(Blueprint.java:727) ~[structurize-1.0.802-1.21.1-snapshot.jar%23989!/:1.0.802-1.21.1-snapshot]
at TRANSFORMER/structurize@1.0.802-1.21.1-snapshot/com.ldtteam.structurize.blueprints.v1.Blueprint.setRotationMirror(Blueprint.java:640) ~[structurize-1.0.802-1.21.1-snapshot.jar%23989!/:1.0.802-1.21.1-snapshot]
at TRANSFORMER/structurize@1.0.802-1.21.1-snapshot/com.ldtteam.structurize.storage.rendering.types.BlueprintPreviewData.applyRotationMirrorAndSync(BlueprintPreviewData.java:329) ~[structurize-1.0.802-1.21.1-snapshot.jar%23989!/:1.0.802-1.21.1-snapshot]
at TRANSFORMER/structurize@1.0.802-1.21.1-snapshot/com.ldtteam.structurize.storage.rendering.types.BlueprintPreviewData.rotate(BlueprintPreviewData.java:244) ~[structurize-1.0.802-1.21.1-snapshot.jar%23989!/:1.0.802-1.21.1-snapshot]
at TRANSFORMER/structurize@1.0.802-1.21.1-snapshot/com.ldtteam.structurize.client.gui.AbstractBlueprintManipulationWindow.rotateRightClicked(AbstractBlueprintManipulationWindow.java:523) ~[structurize-1.0.802-1.21.1-snapshot.jar%23989!/:1.0.802-1.21.1-snapshot]
at TRANSFORMER/structurize@1.0.802-1.21.1-snapshot/com.ldtteam.structurize.client.gui.AbstractBlueprintManipulationWindow.onUnhandledKeyTyped(AbstractBlueprintManipulationWindow.java:301) ~[structurize-1.0.802-1.21.1-snapshot.jar%23989!/:1.0.802-1.21.1-snapshot]
at TRANSFORMER/blockui@1.0.208-1.21.1-snapshot/com.ldtteam.blockui.views.BOWindow.onKeyTyped(BOWindow.java:213) ~[blockui-1.0.208-1.21.1-snapshot.jar%23665!/:1.0.208-1.21.1-snapshot]
at TRANSFORMER/blockui@1.0.208-1.21.1-snapshot/com.ldtteam.blockui.BOScreen.keyPressed(BOScreen.java:154) ~[blockui-1.0.208-1.21.1-snapshot.jar%23665!/:1.0.208-1.21.1-snapshot]
at TRANSFORMER/minecraft@1.21.1/net.minecraft.client.KeyboardHandler.lambda$keyPress$5(KeyboardHandler.java:411) ~[client-1.21.1-20240808.144430-srg.jar%23618!/:?]
at TRANSFORMER/minecraft@1.21.1/net.minecraft.client.gui.screens.Screen.wrapScreenError(Screen.java:451) ~[client-1.21.1-20240808.144430-srg.jar%23618!/:?]
... 26 more
[21Jan2026 17:34:05.703] [Server thread/INFO] [MapFrontiers/]: ServerStoppingEvent done

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[Shadizar]

I can try later in a more minimal instance. Anotehr person with an entirely diff modpack hit it too though.

[Midnightwords]

I'm having the same issue. Here's the crashlog as well.

https://gist.github.com/Midnightwords/43b4f50eaf62b8ebf2533c6f084e2d06

[Shadizar]

In a minimal instance this still occurs

[21Jan2026 18:16:41.197] [Render thread/INFO] [net.minecraft.advancements.AdvancementTree/]: Loaded 332 advancements
[21Jan2026 18:18:22.166] [Server thread/INFO] [minecolonies/]: New Colony Id: 1 by
[21Jan2026 18:18:22.179] [Render thread/INFO] [net.minecraft.client.gui.components.ChatComponent/]: [System] [CHAT] All land within 1 chunks of townhall has been claimed.
[21Jan2026 18:18:22.207] [Render thread/INFO] [net.minecraft.client.gui.components.ChatComponent/]: [System] [CHAT] News spreads swiftly of the newly founded settlement. Before long, pioneers from distant lands will flock to join the ranks of your burgeoning colony.
[21Jan2026 18:18:55.024] [Render thread/INFO] [net.minecraft.client.gui.components.ChatComponent/]: [System] [CHAT] All land within 1 chunks of builder has been claimed.
[21Jan2026 18:18:55.154] [Render thread/INFO] [net.minecraft.client.gui.components.ChatComponent/]: [System] [CHAT] All land within 2 chunks of builder has been claimed.
[21Jan2026 18:19:33.665] [Render thread/ERROR] [net.minecraft.client.Minecraft/FATAL]: Reported exception thrown!
net.minecraft.ReportedException: MousePressed event for BO screen
at TRANSFORMER/minecraft@1.21.1/net.minecraft.client.gui.screens.Screen.wrapScreenError(Screen.java:456) ~[client-1.21.1-20240808.144430-srg.jar%23200!/:?]
at TRANSFORMER/minecraft@1.21.1/net.minecraft.client.MouseHandler.onPress(MouseHandler.java:95) ~[client-1.21.1-20240808.144430-srg.jar%23200!/:?]
at TRANSFORMER/minecraft@1.21.1/net.minecraft.client.MouseHandler.lambda$setup$4(MouseHandler.java:202) ~[client-1.21.1-20240808.144430-srg.jar%23200!/:?]
at TRANSFORMER/minecraft@1.21.1/net.minecraft.util.thread.BlockableEventLoop.execute(BlockableEventLoop.java:98) ~[client-1.21.1-20240808.144430-srg.jar%23200!/:?]
at TRANSFORMER/minecraft@1.21.1/net.minecraft.client.MouseHandler.lambda$setup$5(MouseHandler.java:202) ~[client-1.21.1-20240808.144430-srg.jar%23200!/:?]
at MC-BOOTSTRAP/org.lwjgl.glfw@3.3.3+5/org.lwjgl.glfw.GLFWMouseButtonCallbackI.callback(GLFWMouseButtonCallbackI.java:43) ~[lwjgl-glfw-3.3.3.jar%23173!/:build 5]
at MC-BOOTSTRAP/org.lwjgl@3.3.3+5/org.lwjgl.system.JNI.invokeV(Native Method) ~[lwjgl-3.3.3.jar%23185!/:build 5]
at MC-BOOTSTRAP/org.lwjgl.glfw@3.3.3+5/org.lwjgl.glfw.GLFW.glfwPollEvents(GLFW.java:3438) ~[lwjgl-glfw-3.3.3.jar%23173!/:build 5]
at TRANSFORMER/minecraft@1.21.1/com.mojang.blaze3d.systems.RenderSystem.pollEvents(RenderSystem.java:134) ~[client-1.21.1-20240808.144430-srg.jar%23200!/:?]
at TRANSFORMER/minecraft@1.21.1/com.mojang.blaze3d.systems.RenderSystem.flipFrame(RenderSystem.java:143) ~[client-1.21.1-20240808.144430-srg.jar%23200!/:?]
at TRANSFORMER/minecraft@1.21.1/com.mojang.blaze3d.platform.Window.updateDisplay(Window.java:292) ~[client-1.21.1-20240808.144430-srg.jar%23200!/:?]
at TRANSFORMER/minecraft@1.21.1/net.minecraft.client.Minecraft.runTick(Minecraft.java:1217) ~[client-1.21.1-20240808.144430-srg.jar%23200!/:?]
at TRANSFORMER/minecraft@1.21.1/net.minecraft.client.Minecraft.run(Minecraft.java:807) ~[client-1.21.1-20240808.144430-srg.jar%23200!/:?]
at TRANSFORMER/minecraft@1.21.1/net.minecraft.client.main.Main.main(Main.java:230) ~[client-1.21.1-20240808.144430-srg.jar%23200!/:?]
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[?:?]
at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[?:?]
at MC-BOOTSTRAP/fml_loader@4.0.42/net.neoforged.fml.loading.targets.CommonLaunchHandler.runTarget(CommonLaunchHandler.java:136) ~[loader-4.0.42.jar%23107!/:4.0]
at MC-BOOTSTRAP/fml_loader@4.0.42/net.neoforged.fml.loading.targets.CommonLaunchHandler.clientService(CommonLaunchHandler.java:124) ~[loader-4.0.42.jar%23107!/:4.0]
at MC-BOOTSTRAP/fml_loader@4.0.42/net.neoforged.fml.loading.targets.CommonClientLaunchHandler.runService(CommonClientLaunchHandler.java:32) ~[loader-4.0.42.jar%23107!/:4.0]
at MC-BOOTSTRAP/fml_loader@4.0.42/net.neoforged.fml.loading.targets.CommonLaunchHandler.lambda$launchService$4(CommonLaunchHandler.java:118) ~[loader-4.0.42.jar%23107!/:4.0]
at MC-BOOTSTRAP/cpw.mods.modlauncher@11.0.5/cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:30) [modlauncher-11.0.5.jar%23112!/:?]
at MC-BOOTSTRAP/cpw.mods.modlauncher@11.0.5/cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:53) [modlauncher-11.0.5.jar%23112!/:?]
at MC-BOOTSTRAP/cpw.mods.modlauncher@11.0.5/cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:71) [modlauncher-11.0.5.jar%23112!/:?]
at MC-BOOTSTRAP/cpw.mods.modlauncher@11.0.5/cpw.mods.modlauncher.Launcher.run(Launcher.java:103) [modlauncher-11.0.5.jar%23112!/:?]
at MC-BOOTSTRAP/cpw.mods.modlauncher@11.0.5/cpw.mods.modlauncher.Launcher.main(Launcher.java:74) [modlauncher-11.0.5.jar%23112!/:?]
at MC-BOOTSTRAP/cpw.mods.modlauncher@11.0.5/cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:26) [modlauncher-11.0.5.jar%23112!/:?]
at MC-BOOTSTRAP/cpw.mods.modlauncher@11.0.5/cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:23) [modlauncher-11.0.5.jar%23112!/:?]
at cpw.mods.bootstraplauncher@2.0.2/cpw.mods.bootstraplauncher.BootstrapLauncher.run(BootstrapLauncher.java:210) [bootstraplauncher-2.0.2.jar:?]
at cpw.mods.bootstraplauncher@2.0.2/cpw.mods.bootstraplauncher.BootstrapLauncher.main(BootstrapLauncher.java:69) [bootstraplauncher-2.0.2.jar:?]
Caused by: java.lang.ArrayIndexOutOfBoundsException: Index 2 out of bounds for length 2
at TRANSFORMER/structurize@1.0.802-1.21.1-snapshot/com.ldtteam.structurize.component.CapturedBlock.applyRotationMirror(CapturedBlock.java:81) ~[structurize-1.0.802-1.21.1-snapshot.jar%23211!/:1.0.802-1.21.1-snapshot]
at TRANSFORMER/structurize@1.0.802-1.21.1-snapshot/com.ldtteam.structurize.blueprints.v1.Blueprint.setRotationMirrorRelative(Blueprint.java:727) ~[structurize-1.0.802-1.21.1-snapshot.jar%23211!/:1.0.802-1.21.1-snapshot]
at TRANSFORMER/structurize@1.0.802-1.21.1-snapshot/com.ldtteam.structurize.blueprints.v1.Blueprint.setRotationMirror(Blueprint.java:640) ~[structurize-1.0.802-1.21.1-snapshot.jar%23211!/:1.0.802-1.21.1-snapshot]
at TRANSFORMER/structurize@1.0.802-1.21.1-snapshot/com.ldtteam.structurize.storage.rendering.types.BlueprintPreviewData.applyRotationMirrorAndSync(BlueprintPreviewData.java:329) ~[structurize-1.0.802-1.21.1-snapshot.jar%23211!/:1.0.802-1.21.1-snapshot]
at TRANSFORMER/structurize@1.0.802-1.21.1-snapshot/com.ldtteam.structurize.storage.rendering.types.BlueprintPreviewData.setBlueprint(BlueprintPreviewData.java:222) ~[structurize-1.0.802-1.21.1-snapshot.jar%23211!/:1.0.802-1.21.1-snapshot]
at TRANSFORMER/structurize@1.0.802-1.21.1-snapshot/com.ldtteam.structurize.client.gui.WindowExtendedBuildTool.setBlueprint(WindowExtendedBuildTool.java:1144) ~[structurize-1.0.802-1.21.1-snapshot.jar%23211!/:1.0.802-1.21.1-snapshot]
at TRANSFORMER/structurize@1.0.802-1.21.1-snapshot/com.ldtteam.structurize.client.gui.WindowExtendedBuildTool.handleBlueprintCategory(WindowExtendedBuildTool.java:1069) ~[structurize-1.0.802-1.21.1-snapshot.jar%23211!/:1.0.802-1.21.1-snapshot]
at TRANSFORMER/structurize@1.0.802-1.21.1-snapshot/com.ldtteam.structurize.client.gui.WindowExtendedBuildTool.onButtonClicked(WindowExtendedBuildTool.java:1024) ~[structurize-1.0.802-1.21.1-snapshot.jar%23211!/:1.0.802-1.21.1-snapshot]
at TRANSFORMER/blockui@1.0.208-1.21.1-snapshot/com.ldtteam.blockui.controls.Button.handleClick(Button.java:115) ~[blockui-1.0.208-1.21.1-snapshot.jar%23204!/:1.0.208-1.21.1-snapshot]
at TRANSFORMER/blockui@1.0.208-1.21.1-snapshot/com.ldtteam.blockui.Pane.click(Pane.java:597) ~[blockui-1.0.208-1.21.1-snapshot.jar%23204!/:1.0.208-1.21.1-snapshot]
at TRANSFORMER/blockui@1.0.208-1.21.1-snapshot/com.ldtteam.blockui.views.View.mouseEventProcessor(View.java:438) ~[blockui-1.0.208-1.21.1-snapshot.jar%23204!/:1.0.208-1.21.1-snapshot]
at TRANSFORMER/blockui@1.0.208-1.21.1-snapshot/com.ldtteam.blockui.views.View.mouseClickableEventHandler(View.java:391) ~[blockui-1.0.208-1.21.1-snapshot.jar%23204!/:1.0.208-1.21.1-snapshot]
at TRANSFORMER/blockui@1.0.208-1.21.1-snapshot/com.ldtteam.blockui.views.View.click(View.java:234) ~[blockui-1.0.208-1.21.1-snapshot.jar%23204!/:1.0.208-1.21.1-snapshot]
at TRANSFORMER/blockui@1.0.208-1.21.1-snapshot/com.ldtteam.blockui.views.View.mouseEventProcessor(View.java:438) ~[blockui-1.0.208-1.21.1-snapshot.jar%23204!/:1.0.208-1.21.1-snapshot]
at TRANSFORMER/blockui@1.0.208-1.21.1-snapshot/com.ldtteam.blockui.views.ScrollingContainer.mouseEventProcessor(ScrollingContainer.java:168) ~[blockui-1.0.208-1.21.1-snapshot.jar%23204!/:1.0.208-1.21.1-snapshot]
at TRANSFORMER/blockui@1.0.208-1.21.1-snapshot/com.ldtteam.blockui.views.View.mouseClickableEventHandler(View.java:391) ~[blockui-1.0.208-1.21.1-snapshot.jar%23204!/:1.0.208-1.21.1-snapshot]
at TRANSFORMER/blockui@1.0.208-1.21.1-snapshot/com.ldtteam.blockui.views.View.click(View.java:234) ~[blockui-1.0.208-1.21.1-snapshot.jar%23204!/:1.0.208-1.21.1-snapshot]
at TRANSFORMER/blockui@1.0.208-1.21.1-snapshot/com.ldtteam.blockui.views.View.mouseEventProcessor(View.java:438) ~[blockui-1.0.208-1.21.1-snapshot.jar%23204!/:1.0.208-1.21.1-snapshot]
at TRANSFORMER/blockui@1.0.208-1.21.1-snapshot/com.ldtteam.blockui.views.View.mouseClickableEventHandler(View.java:391) ~[blockui-1.0.208-1.21.1-snapshot.jar%23204!/:1.0.208-1.21.1-snapshot]
at TRANSFORMER/blockui@1.0.208-1.21.1-snapshot/com.ldtteam.blockui.views.View.click(View.java:234) ~[blockui-1.0.208-1.21.1-snapshot.jar%23204!/:1.0.208-1.21.1-snapshot]
at TRANSFORMER/blockui@1.0.208-1.21.1-snapshot/com.ldtteam.blockui.views.View.mouseEventProcessor(View.java:438) ~[blockui-1.0.208-1.21.1-snapshot.jar%23204!/:1.0.208-1.21.1-snapshot]
at TRANSFORMER/blockui@1.0.208-1.21.1-snapshot/com.ldtteam.blockui.views.View.mouseClickableEventHandler(View.java:391) ~[blockui-1.0.208-1.21.1-snapshot.jar%23204!/:1.0.208-1.21.1-snapshot]
at TRANSFORMER/blockui@1.0.208-1.21.1-snapshot/com.ldtteam.blockui.views.View.click(View.java:234) ~[blockui-1.0.208-1.21.1-snapshot.jar%23204!/:1.0.208-1.21.1-snapshot]
at TRANSFORMER/blockui@1.0.208-1.21.1-snapshot/com.ldtteam.blockui.BOScreen.mouseClicked(BOScreen.java:196) ~[blockui-1.0.208-1.21.1-snapshot.jar%23204!/:1.0.208-1.21.1-snapshot]
at TRANSFORMER/minecraft@1.21.1/net.minecraft.client.MouseHandler.lambda$onPress$0(MouseHandler.java:98) ~[client-1.21.1-20240808.144430-srg.jar%23200!/:?]
at TRANSFORMER/minecraft@1.21.1/net.minecraft.client.gui.screens.Screen.wrapScreenError(Screen.java:451) ~[client-1.21.1-20240808.144430-srg.jar%23200!/:?]
... 28 more
[21Jan2026 18:19:33.888] [Server thread/INFO] [net.minecraft.server.MinecraftServer/]: Stopping server

[Shadizar]

Modlist for minimal instance (required mods only)
[18:16:15] [main/INFO]:
Mod List:
Name Version (Mod Id)

	Ars Nouveau 5.11.1 (ars_nouveau)
	Biomes O' Plenty 21.1.0.13 (biomesoplenty)
	Curios API 9.5.1+1.21.1 (curios)
	Domum Ornamentum 1.0.227-snapshot (domum_ornamentum)
	GeckoLib 4 4.8.3 (geckolib)
	GlitchCore 2.1.0.0 (glitchcore)
	Infiniverse 2.0.1.0 (infiniverse)
	LambDynamicLights (API) 4.5.1+1.21.1 (lambdynlights_api)
	MineColonies 1.1.1242-1.21.1-snapshot (minecolonies)
	Minecraft 1.21.1 (minecraft)
	Multi-Piston 1.2.58-1.21.1 (multipiston)
	NeoForge 21.1.217 (neoforge)
	Nuggets 1.0.10.41 (nuggets)
	Structurize 1.0.802-1.21.1-snapshot (structurize)
	TerraBlender 4.1.0.8 (terrablender)
	Towntalk 1.2.0 (towntalk)
	UI Library Mod 1.0.208-1.21.1-snapshot (blockui)

[18:16:16] [main/INFO]: Compatibility level set to JAVA_17
[18:16:16] [main/INFO]: Compatibility level set to JAVA_18
[18:16:16] [main/INFO]: Compatibility level set to JAVA_21

[Shadizar]

On the minimal instance a bit of further data.

1. If you rotate by clicking on the arrows in the gui instad of via keystroke, it crashes in the same way.
2. You can move the preview with the arrow keys and + / - (to move xyz) just fine, and there is no crash.
3. If you hit the green check and assign to builder, and supply the supplies, the build succeeds with no issues.

[armele]

Does this decoration happen to be a 1-block blueprint?

[Thodor12]

Pretty sure this wasn't tested, whenever it was introduced:

return new CapturedBlock(blueprint.getPalette()[blueprint.getPalleteSize()],

This always throws 100% of the time, if you look up in an array with the size of the array, you're always looking up outside of the bounds of the array, not sure who approved this.

The only thing I cannot make sense of, how has this never occurred in the 2 years since this code was made

[Shadizar]

Does this decoration happen to be a 1-block blueprint?

No

[Shadizar]

Pretty sure this wasn't tested, whenever it was introduced:

return new CapturedBlock(blueprint.getPalette()[blueprint.getPalleteSize()],

This always throws 100% of the time, if you look up in an array with the size of the array, you're always looking up outside of the bounds of the array, not sure who approved this.

The only thing I cannot make sense of, how has this never occurred in the 2 years since this code was made

Perhaps some other code that caught the error or otherwise masked, and that code changed?
Just a speculation

[Shadizar]

as it was asked this is the schematic in question

which works flawlessly in 1.20.1 with structurize 797 and minecolonies 1161; I can rotate/mirror like a frantic person and no issues :D

[Shadizar]

So, some neo or mojang change to crash it in 1.21? No idea

[armele]

I am testing a possible fix for this now. @Shadizar, from looking at the schematic, it appears that the tag anchor block is "on" a dirt block, am I seeing that correctly? And a possible stupid question - how did that come to be? I cannot reproduce putting the tag anchor block "on" another block in 1.21. As far as why this isn't seen often, it would only be triggered on decorations with a tag substitution block that had a serialized block entity state. (No idea how common that is, but it is at least not "normal buildings" level of common.)

[Shadizar]

you pickblock a block with a tag anchor in hand to chameleon it
it's common in decos I believe

[Shadizar]

https://minecolonies.com/wiki/items/tag_anchor

"In 1.19+ only (with Structurize 456+), the Tag Anchor can "absorb" another block by using Pick Block (middle-click by default) on a block with the anchor in hand. After placing this special anchor in the world, scanning, and being built, it will turn into the absorbed block instead of into air. This is primarily intended for cases where you want the anchor position somewhere specific but need a non-air block in that position."