> ## Documentation Index
> Fetch the complete documentation index at: https://docs.rageon.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Checker

> Read the Checker, find the piece behind each error, and fix what blocks the export.

The **Checker** is the last section of the details column. It lists what is wrong with the structure. Errors block the export. Warnings do not.

## Read the Checker

Two badges in the header count the problems: red for errors, orange for warnings. With none, the section reads **Ready to export**. Errors come first in the list. The list shows the problems of the active part, but an error in any part blocks the export.

Click a row to select the culprit: the room, portal, prop, light, or opening in the view. A row about textures selects the faces and switches to **Edit geometry**, so you can apply a texture. Some rows point at no piece, such as the empty-structure error, the "No Entrance" error, and the `lodDist` warning. They only describe what to fix.

![Details column with six faces selected and the Material section with a texture, Library, and Import](https://mintcdn.com/rageon/_nzjx4zmIQAxf8Hl/images/structures/structures-checker-ready.webp?fit=max\&auto=format\&n=_nzjx4zmIQAxf8Hl\&q=85\&s=4b704e68ef53e868d8b49ecb8e1a4e48)

A row about missing textures selects those faces and opens the Material section.

## When the export is blocked

Press **Ctrl+E** or **Export** while an error blocks it, and a strip appears over the view: `Export blocked: … problem(s) prevent writing the resource. Click one to mark the culprit.` It lists the blocking rows, and each one works like a row in the Checker. The strip goes away when the problems are fixed or when you close it.

![Plan view with a room and a strip listing no Entrance, an unreachable room, and faces without a texture](https://mintcdn.com/rageon/_nzjx4zmIQAxf8Hl/images/structures/structures-editor-plan.webp?fit=max\&auto=format\&n=_nzjx4zmIQAxf8Hl\&q=85\&s=4a195201d5384821db331a68637654df)

The Export blocked strip over a Plan view, with five problems.

An empty structure is skipped when the project has other content. A structure that only has props or geometry exports without an interior; the Checker only warns.

> [!TIP]
>
> Portals and openings appear by internal id in the Checker and the tree. Click the row instead of looking for the id.

Room and portal messages are explained in [Rooms](/projects/structures/rooms.md) and [Portals and openings](/projects/structures/portals-and-openings.md). The rest are below.

## Troubleshooting

> **Empty structure: create an interior, place a prop or edit the geometry before exporting**
>
> An error: the structure has no rooms, props, or geometry. Draw a room with **Create room**, or add content.

> **No interior: a ymap is produced with the props and the edited geometry, without an MLO.**
>
> A warning: there are props or geometry but no rooms. Add a room if you want an interior.

> **Export replaces the source YMAP/YBN and rebuilds the dependent LODs. Keep the same source files loaded and avoid another resource that replaces these files.**
>
> A warning: the structure replaces map models. Do not run a second resource that replaces the same map files.

> **… without a texture. Click to mark them and apply a texture before exporting.**
>
> An error for faces of the generated shell. Click the row, then **Library** › **Apply texture** in **Material**. See [Textures](/projects/structures/textures.md).

> **… with the texture "…" without a dictionary (.ytd). Click to mark them and choose the texture again.**
>
> An error: the texture lost its texture dictionary. Click the row and choose the texture again from the **Library**.

> **This structure has no shell of its own: only the metadata (.ytyp/.ymap) is produced, without .ydr or .ybn — the geometry and collision remain those of the original interior.**
>
> A warning, expected for an imported interior. Draw rooms to replace the shell. See [Create and import](/projects/structures/create-and-import.md).

> **Room … has no outline capable of generating a floor with collision.**
>
> An error: the outline cannot produce a floor. Fix the outline. See [Rooms](/projects/structures/rooms.md).

> **… room and collision material combinations: the .ybn holds at most 255.**
>
> An error: too many pairs of room and collision material. Use fewer collision materials.

> **An archetype "…" already exists in the game: this structure will overwrite the original.**
>
> A warning: the structure name matches a game interior. Rename the structure unless you want to replace the original. An imported interior is exempt.

> **Timecycle modifier "…" does not touch any room.**
>
> A warning: the modifier's box is outside every room. Move the box.

> **numExitPortals will come out as … (the marked Entrances). The game does not always use that same number, so the original value of this imported MLO may be different — check it if the interior behaves strangely.**
>
> A warning for a re-exported imported interior. It tells you the value that will be written, from the Entrances you marked.

> **The export could not derive this document: …**
>
> An error. Read the reason after the colon and fix that piece.


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