# Maintain Application integrity

> Deleting table items may cause references to be broken. In this case a **Ghost** item will be created to maintain application integrity until the developer can resolve the broken references.

## Introduction

Deleting table items may cause references to be broken. In this case a **Ghost** item will be created to maintain application integrity until the developer can resolve the broken references.

A Ghost can be recognized by the following icon:

![docs image](https://dev-assets.cms.uipath.com/assets/images/process-mining/process-mining-docs-image-54482-a5ea9d7a-6faf2d3c.webp)

:::note
In this guide a ghost of an attribute is used as example. Ghosts of filters, selectors, metrics, and actions can also exist. Normally, you should try to avoid causing ghosts.
:::

Deleting the expression attribute that is used in a dashboard will lead to a broken reference. A Ghost item will be created to maintain application integrity.

## Tools panel

In the lower left-hand corner of the application the **Tools** panel shows that there is a problem in the application. The ghost will be displayed in the **Errors** tab of the **Tools** panel. See illustration below.

See illustration below.

![docs image](https://dev-assets.cms.uipath.com/assets/images/process-mining/process-mining-docs-image-53816-2018b613-60d86d40.webp)

## Resolving Ghosts

Ghost items must not be deleted while there are still references to it from the application. To remove a ghost, you must first replace all references to it.

:::important
Never attempt to delete a ghost while there are still references to it! Doing so may irreparably break your application.
:::

## Viewing the references of a Ghost

Follow this step to see all active references to a ghost attribute.

| Step | Action |
| --- | --- |
| 1 | Double click on the ghost item in the table item list. |

The **Tools** panel shows all references to the ghost item. See illustration below for an example.

![docs image](https://dev-assets.cms.uipath.com/assets/images/process-mining/process-mining-docs-image-53632-dc6124ad-16ce791b.webp)

:::note
You can view the references for any item by right clicking and selecting **Advanced - Show references…**, or by using the **Find In Application** dialog (Ctrl+Shift+F).
:::

## Removing Ghosts

When a ghost item is no longer referenced anywhere, it can be safely removed from the application.

Follow these steps to remove a ghost.

| Step | Action |
| --- | --- |
| 1 | Click on the logo icon and select **Advanced - Delete unused ghosts**. |

:::note
A ghost can also be removed by right clicking and selecting **Delete**. In this case you must verify that there are no references left to the ghost.
:::