---
title: Debug CMS UI
slug: cms-12/docs/debugging-cms-ui
docTags: 
createdAt: 2026-08-10T15:56:01.000Z
---

You can run your site with uncompressed JavaScript in edit view to debug the Optimizely Content Management System (CMS) user interface. To do this, you need to enable debug mode for client resources by using `EPiServer.Framework.Web.Resources.ClientResourceOptions` class add setting the `Debug` property to **true**.

Example configuration:

```csharp
if (_webHostingEnvironment.IsDevelopment()) {
  services.Configure<ClientResourceOptions>(uiOptions => {
    uiOptions.Debug = true;
  });
}
```

The CMS UI NuGet packages contain the JavaScript files required to run the user interface compressed into a zip file. The system then reads the contents of the zip file at run time. At initialization, if the client resources debug flag is set to **true**, the system first looks for a debug version of the JavaScript zip file and, if it exists, loads that instead.

### EPiServer.CMS.UI.Sources

The `EPiServer.CMS.UI.Sources` NuGet package contains all original user interface source files and uncompressed Dojo and Dijit.

The source package is built as part of every release and ties into the continuous release cycle. You can install it like any other NuGet package from [nuget.optimizely.com](http://nuget.optimizely.com/).

```powershell
Install-Package EPiServer.CMS.UI.Sources
```

You can use this package if you need to manipulate source files and create a customized Dojo build. It comes together with Dojo build tools.

:::hint{type="info"}
**Note**
To debug the CMS edit view, you do not need this package. The change described above is sufficient.
:::