Hi,

Include this tag in your web.config file

<runtime>
<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">

<dependentAssembly>
<assemblyIdentity name="System.Web.Extensions" publicKeyToken="31bf3856ad364e35" Culture="neutral"/>

<bindingRedirect oldVersion="3.5.0.0" newVersion="4.0.0.0"/>
<publisherProfile apply="no"/>

</dependentAssembly>
</assemblyBinding>

</runtime>

Regards,

Charan