Here is the stack trace:

ArgumentException
  Column 'proposal_pk' does not belong to table vw_notelist.

Source     : System.Data

Stack Trace:
   at System.Data.DataRow.GetDataColumn(String columnName)
   at System.Data.DataRow.get_Item(String columnName)
   at Trinity.BusinessObjects.boViewNoteLog.get_proposal_pk() in F:\Trinity_new\Trinity\BusinessObjects\boViewNoteLog.Designer.cs:line 824
   at Trinity.Forms.Notes.GetCurrentNote(Int32 tnNote_PK, Boolean tlPutInEditMode) in F:\Trinity_new\Trinity\Forms\Notes.cs:line 109
   at Trinity.Forms.Prospects.EditNote(Boolean tlPutInEditMode) in F:\Trinity_new\Trinity\Forms\Prospects.cs:line 630
   at Trinity.Forms.Prospects.grdNoteLog_DoubleClick(Object sender, EventArgs e) in F:\Trinity_new\Trinity\Forms\Prospects.cs:line 652
   at System.Windows.Forms.Control.OnDoubleClick(EventArgs e)
   at System.Windows.Forms.DataGridView.OnDoubleClick(EventArgs e)
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.DataGridView.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativewindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativewindow.WndProc(Message& m)
   at System.Windows.Forms.Nativewindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

What's even stranger is that this was all working 10 minutes ago!

The SP was not returning the column...