RadDatePicker exception on attempt to access UseColumnHeadersAsSelectors

[Erin]

Hello,
I am trying to use a Prometheus RadDatePicker and am encountering an error.  The RadDatePicker code is:

<telerik:RadDatePicker ID="dateExpirationDate" MinDate="<%#DateTime.Today.AddDays(1) %>" Calendar-Skin="WebBlue" runat="server" ></telerik:RadDatePicker>

The error is below.  Thanks in advance for your help...

[MethodAccessException: Attempt to access the method failed.]
   System.Reflection.MethodBase.PerformSecurityCheck(Object obj, RuntimeMethodHandle method, IntPtr parent, UInt32 invocationFlags) +0
   System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) +218
   System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) +29
   System.ComponentModel.ReflectPropertyDescriptor.GetValue(Object component) +86

[TargetInvocationException: Property accessor 'UseColumnHeadersAsSelectors' on object 'Telerik.Web.UI.DatePickingCalendar' threw the following exception:'Attempt to access the method failed.']
   System.ComponentModel.ReflectPropertyDescriptor.GetValue(Object component) +370
   System.ComponentModel.ReflectPropertyDescriptor.ShouldSerializeValue(Object component) +342
   Telerik.Web.ScriptObjectBuilder.DescribeComponent(Object instance, ScriptComponentDescriptor descriptor, IUrlResolutionService urlResolver, IControlResolver controlResolver) +948
   Telerik.Web.UI.ScriptRegistrar.GetScriptDescriptors(WebControl control) +199
   Telerik.Web.UI.RadWebControl.GetScriptDescriptors() +44
   Telerik.Web.UI.RadWebControl.System.Web.UI.IScriptControl.GetScriptDescriptors() +47
   System.Web.UI.ScriptControlManager.RegisterScriptDescriptors(IScriptControl scriptControl) +127
   System.Web.UI.ScriptManager.RegisterScriptDescriptors(IScriptControl scriptControl) +52
   Telerik.Web.UI.RadWebControl.RegisterScriptDescriptors() +55
   Telerik.Web.UI.RadWebControl.Render(HtmlTextWriter writer) +90
   Telerik.Web.UI.RadCalendar.Render(HtmlTextWriter writer) +634
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +25
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +121
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +22
   System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +130
   System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +24
   Telerik.Web.UI.RadDatePicker.RenderChildren(HtmlTextWriter writer) +464
   System.Web.UI.WebControls.WebControl.RenderContents(HtmlTextWriter writer) +7
...

[Pavel]

Hello Erin,

Could you provide more details about the scenario in which the error is thrown? Does that happen on page load or when you do something specific on the page? Do you have any code in the code-behind that concerns the RadDatePicker? Any other information that will help reproduce the error is welcome.

Thank you for your cooperation.

Regards,
Pavel
the Telerik team

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[Erin]

Hello,
Thanks for your reply.  I tried to simplify the usage as much as possible and found that the error still occurs on a test page I created that has nothing else on it but the RadDatePicker control.  In the code behind, there is nothing but empty page event functions that I used to put breakpoints in to see where in the page lifecycle the error occurs.  The error occurs sometime after the Page_PreRender event.  Could there be something wrong with my web.config that is causing the problem?
Thanks for your help!
Erin

[Konstantin Petkov]

Hi Erin,

Is this the latest RadControls Prometheus version that you are using? If so, we will kindly ask you to submit a regular support ticket where you can send a runnable sample simplified as much as possible. We will investigate the issue and get back to you with resolution.

All the best,
Konstantin Petkov
the Telerik team

Instantly find answers to your questions at the new Telerik Support Center

[Nick Dresher]

Has this issue been resolved?  I am not experiencing it on my on machine, but when I move the application to a different server I am getting this same error.

Thanks,
Tony

[Pavel]

Hi Nick,

Since we could not reproduce the error, the reason for it to appear is unknown to us. Our guess is that it my be a security/permissions-related problem. You should note that we do not support Low trust level and if the server is running with such security settings, our controls might not work.

Greetings,
Pavel
the Telerik team

Instantly find answers to your questions at the new Telerik Support Center

[Erin]

Hello,
I just wanted to make a note that the problem disappeared for me in one of my later builds so I didn't follow up with it further.  I don't know what it was that fixed it and it may have been related to the security settings as Nick suggested.