Compilation issue with ascx controls.

I have a bunch of ascx controls which I am loading at runtime.   Below is an example. 
if (e.PageView.ID.StartsWith("Submissions"))
{
controls_SubmissionsList submissionsList = (controls_SubmissionsList)LoadControl("controls/submissionslist.ascx");
submissionsList.InquiryId = Convert.ToInt32(e.PageView.ID.Remove(0, 11));
e.PageView.Controls.Add(submissionsList);
}
 Each time I edit anything in the App_Code directory and try and run it I get the error:

     Error 1 The type or namespace name 'controls_SubmissionsList' could not be found (are you missing a using directive or an assembly reference?) c:\SCID\SCID.Web\Default.aspx.cs 40 13 c:\SCID\SCID.Web\

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