# Telerik Controls Do Not Work If a Compression Module Is Used in the Project

## Environment

<table>
	<tbody>
		<tr>
			<td>Product</td>
			<td>Progress® Telerik® UI for ASP.NET AJAX</td>
		</tr>
	</tbody>
</table>

## Description

When working with Telerik UI for ASP.NET AJAX, the Telerik controls are not working if the project or website uses the Compression module.

## Cause

The possible reason for this issue is that a double compression of web resources occurs. The web resources requested by the Telerik controls are compressed twice—once by the `Script`, `RadScript`, or `RadStyleSheet` Manager and a second time by the Compression module.

## Solution

To solve this issue, skip the compression for the requested resource in the Compression module. If the `OutputCompression` property of the `RadScriptManager` or the `RadStyleSheetManager` is set to `Disabled`, you can configure the Compression module to compress `Telerik.Web.UI.WebResource.axd`.

| Control                | Requested Resources                     |
| ---------------------- | --------------------------------------- |
| `ScriptManager`        | `WebResource.axd`, `ScriptResource.axd` |
| `RadScriptManager`     | `Telerik.Web.UI.WebResource.axd`        |
| `RadStyleSheetManager` | `Telerik.Web.UI.WebResource.axd`        |