Object reference not set to an instance of an object

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C#

We migrated our web application VS 2008 to VS 2010 and EntitySpaces 2007 to EntitySpaces 2010. Here we are phasing an issue while saving an entity.

Issue is:
we have a formview in aspx page and it is using "ObjectDatasource" as datasource. Formview has couple of controls like "Textbox" and "dropdownlist". When we are adding new data and click save, then Formview.DataBind() is giving an error:

Error :Object reference not set to an instance of an object.

Stack Trace:
System.NullReferenceException was unhandled by user code
  Message=Object reference not set to an instance of an object.
  Source=EntitySpaces.Core
  StackTrace:
       at EntitySpaces.Core.esEntity.System.ComponentModel.ICustomTypeDescriptor.GetProperties(Attribute[] attributes)
       at EntitySpaces.Core.esEntity.System.ComponentModel.ICustomTypeDescriptor.GetProperties()
       at System.ComponentModel.TypeDescriptor.MergedTypeDescriptor.System.ComponentModel.ICustomTypeDescriptor.GetProperties()
       at System.ComponentModel.TypeDescriptor.GetPropertiesImpl(Object component, Attribute[] attributes, Boolean noCustomTypeDesc, Boolean noAttributes)
       at System.Web.UI.DataBinder.GetPropertiesFromCache(Object container)
       at System.Web.UI.DataBinder.GetPropertyValue(Object container, String propName)
       at System.Web.UI.WebControls.FormView.CreateChildControls(IEnumerable dataSource, Boolean dataBinding)
       at System.Web.UI.WebControls.CompositeDataBoundControl.PerformDataBinding(IEnumerable data)
       at System.Web.UI.WebControls.FormView.PerformDataBinding(IEnumerable data)
       at System.Web.UI.WebControls.DataBoundControl.OnDataSourceViewSelectCallback(IEnumerable data)
       at System.Web.UI.DataSourceView.Select(DataSourceSelectArguments arguments, DataSourceViewSelectCallback callback)
       at System.Web.UI.WebControls.DataBoundControl.PerformSelect()
       at System.Web.UI.WebControls.BaseDataBoundControl.DataBind()
       at System.Web.UI.WebControls.FormView.DataBind()
       at Rules_Rules_Rule.PopulateRule() in C:\05272011\Backup_fully working 3.0\Web_Updated_Framework\Visa.IntelliLink.WebApp\Rules\Rules\Rule.aspx.cs:line 322
       at Rules_Rules_Rule.GridViewRules_RowCommand(Object sender, GridViewCommandEventArgs e) in C:\05272011\Backup_fully working 3.0\Web_Updated_Framework\Visa.IntelliLink.WebApp\Rules\Rules\Rule.aspx.cs:line 312
       at System.Web.UI.WebControls.GridView.OnRowCommand(GridViewCommandEventArgs e)
       at System.Web.UI.WebControls.GridView.HandleEvent(EventArgs e, Boolean causesValidation, String validationGroup)
       at System.Web.UI.WebControls.GridView.OnBubbleEvent(Object source, EventArgs e)
       at System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args)
       at System.Web.UI.WebControls.GridViewRow.OnBubbleEvent(Object source, EventArgs e)
       at System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args)
       at System.Web.UI.WebControls.LinkButton.OnCommand(CommandEventArgs e)
       at PeterBlum.DES.LinkButton.OnCommand(CommandEventArgs e)
       at System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument)
       at System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
       at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)
       at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
       at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
  InnerException: 

Thanks in advance.