DevExpress ASPxGridView works fine in mojoPortal
In your web project make sure you have added references to these:
For the version you are using...
DevExpress.Web.v10.2
DevExpress.Web.ASPxGridView.v10.2
DevExpress.Web.ASPxEditors.v10.2
DevExpress.Data.v10.2
Also this should all be in your Web.config for the version you are using:
<configSections>
<sectionGroup name="devExpress">
<section name="settings" type="DevExpress.Web.ASPxClasses.SettingsConfigurationSection, DevExpress.Web.v10.2, Version=10.2.5.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" requirePermission="false" />
<section name="compression" type="DevExpress.Web.ASPxClasses.CompressionConfigurationSection, DevExpress.Web.v10.2, Version=10.2.5.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" requirePermission="false" />
<section name="themes" type="DevExpress.Web.ASPxClasses.ThemesConfigurationSection, DevExpress.Web.v10.2, Version=10.2.5.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" requirePermission="false" />
<section name="errors" type="DevExpress.Web.ASPxClasses.ErrorsConfigurationSection, DevExpress.Web.v10.2, Version=10.2.5.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" requirePermission="false" />
</sectionGroup>
</configSections>
<httpModules>
<add type="DevExpress.Web.ASPxClasses.ASPxHttpHandlerModule, DevExpress.Web.v10.2, Version=10.2.5.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" name="ASPxHttpHandlerModule" />
</httpModules>
<compilation debug="true" defaultLanguage="C#" targetFramework="4.0">
<assemblies>
<add assembly="DevExpress.Web.ASPxGridView.v10.2, Version=10.2.5.0, Culture=neutral, PublicKeyToken=B88D1754D700E49A" />
<add assembly="DevExpress.Web.ASPxEditors.v10.2, Version=10.2.5.0, Culture=neutral, PublicKeyToken=B88D1754D700E49A" />
<add assembly="DevExpress.Web.v10.2, Version=10.2.5.0, Culture=neutral, PublicKeyToken=B88D1754D700E49A" />
<add assembly="DevExpress.Data.v10.2, Version=10.2.5.0, Culture=neutral, PublicKeyToken=B88D1754D700E49A" />
</assemblies>
</compilation>
</modules>
<add type="DevExpress.Web.ASPxClasses.ASPxHttpHandlerModule, DevExpress.Web.v10.2, Version=10.2.5.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" name="ASPxHttpHandlerModule" />
</modules>
<devExpress>
<settings rightToLeft="false" />
<compression enableHtmlCompression="false" enableCallbackCompression="true" enableResourceCompression="true" enableResourceMerging="false" />
<themes enableThemesAssembly="true" />
<errors callbackErrorRedirectUrl="" />
</devExpress>
</configuration>
Hope this helps
Rick