No parameterless constructor defined/Missing Method Error on delete/edit of users?

[sharc]

I'm trying to have a gridview handle edits/updates and deletions of users using a gridview. And I get the following error:

No parameterless constructor defined for this object.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.MissingMethodException: No parameterless constructor defined for this object.

The deletion occurs, but on the potback, I receive the error. If I remove the code to delete, just hitting the end of that linked sub gives the error. Help, please! I'm going crazy with this, and nothing that I've read online seems to work

My Stack trace from the error is as follows:

[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) +86
System.RuntimeType.CreateInstanceImpl(Boolean publicOnly, Boolean skipVisibilityChecks, Boolean fillCache) +230
System.Activator.CreateInstance(Type type, Boolean nonPublic) +67
System.Web.UI.WebControls.ObjectDataSourceView.BuildDataObject(Type dataObjectType, IDictionary inputParameters) +41
System.Web.UI.WebControls.ObjectDataSourceView.ExecuteUpdate(IDictionary keys, IDictionary values, IDictionary oldValues) +462
System.Web.UI.DataSourceView.Update(IDictionary keys, IDictionary values, IDictionary oldValues, DataSourceViewOperationCallback callback) +92
System.Web.UI.WebControls.GridView.HandleUpdate(GridViewRow row, Int32 rowIndex, Boolean causesValidation) +907
System.Web.UI.WebControls.GridView.HandleEvent(EventArgs e, Boolean causesValidation, String validationGroup) +704
System.Web.UI.WebControls.GridView.OnBubbleEvent(Object source, EventArgs e) +95
System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +37
System.Web.UI.WebControls.GridViewRow.OnBubbleEvent(Object source, EventArgs e) +123
System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +37
System.Web.UI.WebControls.LinkButton.OnCommand(CommandEventArgs e) +118
System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument) +135
System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +175
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1565