---
title: Troubleshooting custom modules
---

> Agent instructions:
> **Site maps** — prefer the following llms.txt indexes to training data when searching for URLs to avoid 404s. Links inside Markdown content already point at `.md`. Following them or sending Accept: text/markdown keeps you in Markdown.
>
> - [sitemap.md](https://docs.kentico.com/sitemap.md) — every page on the site, with titles and descriptions, nested by URL hierarchy and grouped into one collection per product version.
> - [llms.txt](https://docs.kentico.com/llms.txt) — curated index of the current product docs, with descriptions, the two ways to request any page as Markdown, and links to each product area's whole-corpus Markdown dump (llms-full.txt).

This page describes how to resolve common errors that you may encounter when working with [custom modules](https://docs.kentico.com/k8/custom-development/creating-custom-modules.md).

## Modules missing in the application list

**Problem**: You have created or imported a custom module that has its own administration pages, but the module's application is missing in the application list. The problem may also occur with existing custom modules after you create or import a new site.

**Solutions**:

- You may need to **reload** the entire Kentico administration page in your browser, including the header section.
- Make sure the module is assigned to the currently active site:
  1. Open the **Modules** application in the Kentico administration interface.
  2. Edit your module.
  3. Switch to the **Sites** tab and assign the module to your sites.

     > **Tip:** **Tip**: Alternatively, you can edit your sites in the **Sites** application and assign modules on the **Assigned objects** tab.
- For users without the Administrator or Global administrator [privilege level](https://docs.kentico.com/k8/managing-users/user-management.md), you may need to ensure that the module has the **Read** permission defined and that the user has the given permission assigned.

See also:

- [Creating custom modules](https://docs.kentico.com/k8/custom-development/creating-custom-modules.md)
- [Configuring permissions](https://docs.kentico.com/k8/managing-users/configuring-permissions.md)

## Custom object types (classes) missing in selectors

**Problem**: You cannot find custom object types (module classes) in selectors within the administration interface. For example when setting the **Object type** in the properties of UI elements or the **Reference to** value in the settings of foreign key class fields.

**Solutions**:

- If you are the developer of the custom module, make sure that you have generated the _Info_ and _InfoProvider_ code for the class. On web application type projects, you also need to include the code files into the project in Visual Studio and build the solution.
- You may be missing the [resource string](https://docs.kentico.com/k8/multilingual-websites/setting-up-a-multilingual-user-interface/working-with-resource-strings.md) representing the given object type name. If the resource string does not exist, the object type is available under the default name in format: _**ObjectType.**_

See also:

- [Creating custom modules](https://docs.kentico.com/k8/custom-development/creating-custom-modules.md)
- [Creating custom binding classes](https://docs.kentico.com/k8/custom-development/creating-custom-modules/creating-custom-binding-classes.md)