> For the complete documentation index, see [llms.txt](https://rtx-dev.gitbook.io/rtxdev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://rtx-dev.gitbook.io/rtxdev/rtx-shell-creator/guides/checks-undo-and-history.md).

# Checks, Undo & History

Find problems, fix them in one click and go back to any version.

{% hint style="info" %}
**Watch it:** [Housing points & checks - 5:16](https://www.youtube.com/watch?v=EPpvW_mne4Y\&t=316s) · [Undo - 1:26](https://www.youtube.com/watch?v=EPpvW_mne4Y\&t=86s)
{% endhint %}

## Checks

The **Checks** button in the top bar is green when everything is fine, or shows how many things to check. The **Checks** tab lists them. Click a row to select the problem, and **Fix** to fix it.

<figure><img src="https://1804361591-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FCGSsnvBAI11nCFRWfpsr%2Fuploads%2FxWF62BxHPHeTZlR5HEV8%2Fshell-creator-checks.webp?alt=media" alt="The Checks tab"><figcaption><p>The Checks tab - every problem with a Fix button.</p></figcaption></figure>

| Check                                    | Fix                                        |
| ---------------------------------------- | ------------------------------------------ |
| No rooms yet                             | Draw walls that close a space              |
| A wall end is not joined                 | Joins it to the nearest wall or removes it |
| No exit point                            | Puts it by the front door                  |
| Exit point outside the rooms             | Moves it by the front door                 |
| No management, wardrobe or storage point | Puts it in a fitting room                  |
| A room has no door                       | Adds a door to the room next to it         |
| A room has no name                       | Names it after its type                    |
| A room has no ceiling light              | Adds one in the middle                     |
| A window between two rooms               | Turns it into an open pass-through         |
| Two openings overlap                     | Moves one to a free spot                   |
| Stairs with no floor above               | Adds a new floor                           |
| Stairs go through a wall                 | Moves them to the nearest free spot        |
| Ladder with no floor above               | Adds a floor                               |
| A prop outside the rooms                 | Removes it                                 |
| More props than the limit                | Removes the extra ones                     |
| Very many pieces                         | The shell may load slowly                  |

{% hint style="info" %}
Finish warns you when serious problems are left, but still lets you build.
{% endhint %}

***

## Undo & Redo

* `Ctrl + Z` undo, `Ctrl + Y` or `Ctrl + Shift + Z` redo
* 120 steps
* One paint stroke is one step

***

## History

The **History** tab keeps the versions of your shell.

* **Save a version** with your own name
* An **automatic version** is saved at most every 3 minutes while you edit, and before every restore
* The last **30 versions** are kept, with who saved them and when
* **Restore** puts the shell back for everyone editing it. The current state is saved first

{% hint style="success" %}
Shells are saved automatically, 2.5 seconds after every change and when the resource stops.
{% endhint %}