Object reference not set to an instance of an object

I got the followings error message when I deployed the website to web server
Type: System.NullReferenceException
Message: Object reference not set to an instance of an object.
Source: System.Web.Extensions
TargetSite: System.Web.Script.Services.WebServiceData GetWebServiceData(System.Web.HttpContext, System.String, Boolean, Boolean)
Stack Trace:
at System.Web.Script.Services.WebServiceData.GetWebServiceData(HttpContext context, String virtualPath, Boolean failIfNoData, Boolean pageMethods)
at System.Web.Script.Services.PageClientProxyGenerator.GetClientProxyScript(HttpContext context, IPage page, Boolean debug)
at System.Web.UI.ScriptManager.RegisterServices()
at System.Web.UI.ScriptManager.OnPagePreRenderComplete(Object sender, EventArgs e)
at System.EventHandler.Invoke(Object sender, EventArgs e)
at System.Web.UI.Page.OnPreRenderComplete(EventArgs e)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)


Turn on "Allow this precompiled site to be updatable" and "Use fixed naming and single page assemblies"