Unrecognized configuration section system.web.extensions - .net-4.0

Question

I created a web site using .NET 4.0 with JSON. I am now trying to host the site on a remote host server (Network Solutions) and I get the following error when I open the web site:
Unrecognized configuration section system.web.extensions in web.config file.
I called their support and they said they can only host .NET 3.5 web sites and not .NET 4.0 (they don't have .NET 4.0 framework on their servers).
Is there a workaround to make this work in a .NET 3.5 framework?
Here is my config file:
<?xml version="1.0"?>
<configuration>
<configSections>
<sectionGroup name="myCompany.PropertySystem" type="myCompany.PropertySystem.Configuration.PropertyConfigurationSectionGroup">
<section name="dataProviders" type="myCompany.PropertySystem.Configuration.PropertyDataProviderConfigurationSection, myCompany.PropertySystem"/>
</sectionGroup>
</configSections>
<system.web>
<globalization culture="en-US" uiCulture="en-US"/>
<compilation debug="true" targetFramework="4.0" defaultLanguage="c#">
</compilation>
<authentication mode="Forms">
<forms loginUrl="~/Login.aspx" />
</authentication>
<httpHandlers>
<remove verb="*" path="*.asmx"/>
<add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
<add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
<add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
<add verb="GET, POST" path="Upload.ashx" type="myCompany.PropertySystem.Web.Handlers.UploadHandler, myCompany.PropertySystem"/>
</httpHandlers>
<httpModules>
<add name="SriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
</httpModules>
<trace enabled="false" pageOutput="true" mostRecent="true" requestLimit="150"/>
<customErrors mode="Off"></customErrors>
<pages validateRequest="false" enableViewState="false" enableEventValidation="false" controlRenderingCompatibilityVersion="3.5">
<controls>
<add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
<add tagPrefix="asp" namespace="System.Web.UI.WebControls" assembly="System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
</controls>
</pages>
<webServices>
<protocols>
<add name="HttpGet"/>
</protocols>
</webServices>
<sessionState mode="InProc" cookieless="UseCookies" timeout="120"></sessionState>
<httpRuntime executionTimeout="120" maxRequestLength="524288"/>
</system.web>
<system.web.extensions>
<scripting>
<webServices>
<jsonSerialization maxJsonLength="500000000"/>
</webServices>
</scripting>
</system.web.extensions>
<system.webServer>
<validation validateIntegratedModeConfiguration="false"/>
<handlers>
<remove name="WebServiceHandlerFactory-Integrated"/>
<remove name="ScriptHandlerFactory"/>
<remove name="ScriptHandlerFactoryAppServices"/>
<remove name="ScriptResource"/>
<add name="ScriptHandlerFactory" verb="*" path="*.asmx" preCondition="integratedModule" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
<add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedModule" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
<add name="ScriptResource" verb="GET,HEAD" path="ScriptResource.axd" preCondition="integratedModule" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
<add name="Upload" verb="GET,POST" path="Upload.ashx" type="myCompany.PropertySystem.Web.Handlers.UploadHandler, myCompany.PropertySystem"/>
</handlers>
<defaultDocument>
<files>
<remove value="iisstart.htm"/>
<remove value="index.html"/>
<remove value="index.htm"/>
<remove value="Default.asp"/>
<remove value="Default.htm"/>
</files>
</defaultDocument>
</system.webServer>
<appSettings>
<add key="SiteID" value="700"/>
<add key="SiteName" value="My Company"/>
<add key="SiteVirtualPath" value="~/"/>
<add key="StartPage" value="~/Default.aspx"/>
<!-- Email server values-->
<add key="SmtpServer.Name" value=""/>
<add key="SmtpServer.Port" value=""/>
<add key="SmtpServer.UserName" value=""/>
<add key="SmtpServer.Password" value=""/>
<add key="Notifications.From" value=""/>
<add key="Notifications.To" value=""/>
<add key="Notifications.Cc" value=""/>
<add key="HandlerAcceptedReferrers" value=""/>
<!-- Upload path-->
<add key="UploadPath" value="~/Uploads"/>
<add key="PropertyApplicationServerUrl" value="http://localhost/PropertySystem/"/>
<add key="RedirectToPropertyApplicationUrl" value="false"/>
</appSettings>
<connectionStrings>
<add name="myCompany.PropertySystem.Data.Providers.PropertyManagementDataProvider" connectionString="Data Source=MYCOMPANY;Initial Catalog=MyCompanyDB;User ID=sa;Password=somepwd;Persist Security Info=False;" providerName="System.Data.SqlClient"/>
</connectionStrings>
<myCompany.PropertySystem>
<dataProviders>
<dataProvider name="PropertyManagementDataProvider" providerType="myCompany.PropertySystem.Data.Providers.PropertyManagementDataProvider, myCompany.PropertySystem" connectionString="#myCompany.PropertySystem.Data.Providers.PropertyManagementDataProvider" defaultSchema="dbo" defaultCommandTimeout="120" cachingEnabled="true" defaultCacheDuration="00.00:30:00">
</dataProvider>
</dataProviders>
</myCompany.PropertySystem>
</configuration>

Answer 1

Yes, you should check the iis application pool and make sure it is running .net 4.0. (Right click on the site in iis and see the property, and you should be able to change the framework it uses there too.)
and make sure you run "iisreset" command in command prompt later.