Hi 

We have installed Contour 3.0.20 on an Umbraco v6.1.6 instance. It was installed as a package and the installation completed successfully. We can access the contour tools and can add and edit forms.

Our issue is If we add a Radio Button List, Checkbox List or Drop down list onto a form we get a 500 error after pressing save. We then get a 500 error when you view the form. The error occurs if we added items to the list and and if we leave the list empty.

The error message in the Umbraco log file is:

2014-04-30 13:05:08,219 [27] ERROR Umbraco.Core.UmbracoApplicationBase - [Thread 81] An unhandled exception occurred
System.Web.HttpUnhandledException (0x80004005): Exception of type 'System.Web.HttpUnhandledException' was thrown. ---> System.NullReferenceException: Object reference not set to an instance of an object.
   at Umbraco.Forms.Core.Providers.Prevalues.Standard.GetPreValues(Field field) in c:\Program Files (x86)\teamcity\buildAgent\work\fdc2f0fcbbcef310\Umbraco.Forms.Core.Providers\Prevalues\Standard.cs:line 26
   at Umbraco.Forms.UI.Usercontrols.EditForm.RenderFieldPreview(Field f)
   at ASP.usercontrols_umbracocontour_editform_ascx.__DataBind__control21(Object sender, EventArgs e)
   at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding)
   at System.Web.UI.Control.DataBindChildren()
   at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding)
   at System.Web.UI.WebControls.Repeater.CreateItem(Int32 itemIndex, ListItemType itemType, Boolean dataBind, Object dataItem)
   at System.Web.UI.WebControls.Repeater.CreateControlHierarchy(Boolean useDataSource)
   at System.Web.UI.WebControls.Repeater.OnDataBinding(EventArgs e)
   at Umbraco.Forms.UI.Usercontrols.EditForm.RenderFieldset(Object sender, RepeaterItemEventArgs e)
   at System.Web.UI.WebControls.Repeater.CreateItem(Int32 itemIndex, ListItemType itemType, Boolean dataBind, Object dataItem)
   at System.Web.UI.WebControls.Repeater.CreateControlHierarchy(Boolean useDataSource)
   at System.Web.UI.WebControls.Repeater.OnDataBinding(EventArgs e)
   at Umbraco.Forms.UI.Usercontrols.EditForm.RenderPage(Object sender, RepeaterItemEventArgs e)
   at System.Web.UI.WebControls.Repeater.CreateItem(Int32 itemIndex, ListItemType itemType, Boolean dataBind, Object dataItem)
   at System.Web.UI.WebControls.Repeater.CreateControlHierarchy(Boolean useDataSource)
   at System.Web.UI.WebControls.Repeater.OnDataBinding(EventArgs e)
   at Umbraco.Forms.UI.Usercontrols.EditForm.Page_Load(Object sender, EventArgs e)
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   at System.Web.UI.Page.HandleError(Exception e)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   at System.Web.UI.Page.ProcessRequest()
   at System.Web.UI.Page.ProcessRequest(HttpContext context)
   at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)