I thought the stack trace may help on this
[MissingMethodException: No parameterless constructor defined for this
object.]
System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean
publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandle& ctor,
Boolean& bNeedSecurityCheck) +0
System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean
fillCache) +103
System.RuntimeType.CreateInstanceImpl(Boolean publicOnly, Boolean
skipVisibilityChecks, Boolean fillCache) +261
System.Activator.CreateInstance(Type type, Boolean nonPublic) +66
System.Web.UI.WebControls.ObjectDataSourceView.InvokeMethod(ObjectDataSourceMethod method, Boolean disposeInstance, Object& instance) +127
System.Web.UI.WebControls.ObjectDataSourceView.InvokeMethod(ObjectDataSourceMethod method) +38
System.Web.UI.WebControls.ObjectDataSourceView.ExecuteDelete(IDictionary
keys, IDictionary oldValues) +1110
System.Web.UI.DataSourceView.Delete(IDictionary keys, IDictionary
oldValues, DataSourceViewOperationCallback callback) +75
System.Web.UI.WebControls.FormView.HandleDelete(String commandArg) +855
System.Web.UI.WebControls.FormView.HandleEvent(EventArgs e, Boolean
causesValidation, String validationGroup) +784
System.Web.UI.WebControls.FormView.OnBubbleEvent(Object source, EventArgs
e) +95
System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +35
System.Web.UI.WebControls.FormViewRow.OnBubbleEvent(Object source,
EventArgs e) +109
System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +35
System.Web.UI.WebControls.LinkButton.OnCommand(CommandEventArgs e) +115
System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String
eventArgument) +134
System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +7
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler
sourceControl, String eventArgument) +11
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +180
System.Web.UI.Page.ProcessRequestMain(Boolean
includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5670