Archivo web.config de ejemplo para Crystal Reports 2008:

Debe configurarlo o fusionarlo con su propio web.config dependiendo de su aplicación.

<?xml version="1.0"?>
<!--
    Note: As an alternative to hand editing this file you can use the
    web admin tool to configure settings for your application. Use
    the Website->Asp.Net Configuration option in Visual Studio.
    A full list of settings and comments can be found in
    machine.config.comments usually located in
    \Windows\Microsoft.Net\Framework\v2.x\Config
-->
<configuration>
<appSettings>
<add key="CrystalImageCleaner-AutoStart" value="true"/>
<add key="CrystalImageCleaner-Sleep" value="60000"/>
<add key="CrystalImageCleaner-Age" value="120000"/>
</appSettings>
<connectionStrings/>
<system.web>
<!--
            Set compilation debug="true" to insert debugging
            symbols into the compiled page. Because this
            affects performance, set this value to true only
            during development.
        -->
<compilation debug="true">
<assemblies>
<add assembly="CrystalDecisions.Web, Version=12.0.2000.0, Culture=neutral,
PublicKeyToken=692FBEA5521E1304"/>
<add assembly="CrystalDecisions.Shared, Version=12.0.2000.0,
Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
<add assembly="CrystalDecisions.ReportSource, Version=12.0.2000.0,
Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
<add assembly="CrystalDecisions.Enterprise.Framework, Version=12.0.1100.0,
Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
<add assembly="CrystalDecisions.Enterprise.Desktop.Report,
Version=12.0.1100.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
<add assembly="CrystalDecisions.ReportAppServer.Controllers,
Version=12.0.1100.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
<add assembly="CrystalDecisions.CrystalReports.Engine, Version=12.0.2000.0,
Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
<add assembly="CrystalDecisions.Enterprise.InfoStore, Version=12.0.1100.0,
Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
<add assembly="CrystalDecisions.Enterprise.Viewing.ReportSource,
Version=12.0.1100.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/><add
assembly="CrystalDecisions.ReportAppServer.ClientDoc, Version=12.0.1100.0,
Culture=neutral, PublicKeyToken=692fbea5521e1304"/>
<add assembly="CrystalDecisions.ReportAppServer.CommonObjectModel,
Version=12.0.1100.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
<add assembly="CrystalDecisions.ReportAppServer.DataDefModel,
Version=12.0.1100.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
<add assembly="CrystalDecisions.ReportAppServer.ObjectFactory,
Version=12.0.1100.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
<add assembly="CrystalDecisions.ReportAppServer.ReportDefModel,
Version=12.0.1100.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
<add assembly="CrystalDecisions.CrystalReports.TemplateEngine,
Version=12.0.1100.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
</assemblies>
</compilation>
<httpHandlers>
<add verb="GET" path="CrystalImageHandler.aspx"
type="CrystalDecisions.Web.CrystalImageHandler, CrystalDecisions.Web,
Version=12.0.3700.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/>
<add verb="GET" path="CrystalImageHandler.aspx"
type="CrystalDecisions.Web.CrystalImageHandler, CrystalDecisions.Web,
Version=12.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/>
</httpHandlers>
</system.web>
</configuration>