Calculating field values to NULL results in 'Error running VBA code : User interrupt'

Description

When the Field Calculator is used to calculate a field value to NULL using the equation [Field name] = is null, the following error displays:

"Error running VBA code : User interrupt."

Cause

It is not possible to calculate a field value to NULL using the Field Calculator. The calculation must be done using VBA and ArcObjects.

Solution or Workaround

Warning:
This code does not edit a selection set. It edits the whole table and the edits cannot be undone.

1. Start ArcMap.
2. Open the Visual Basic Editor.
   
   
   In ArcMap, select Tools > Macros > Visual Basic Editor.
   
   
3. In the Project Explorer window, expand Project and select ArcMap Objects > ThisDocument. Right-click on ThisDocument and select View Code.
   
   

   Note:
   Code in the project's ThisDocument code module only runs in the current map document. To store the code in all map documents, open the Normal.mxt ThisDocument code module instead.

   
   
4. Paste the following code into the code module. Substitute "FieldName" with the name of the desired field in quotes.
   

   Code:
   Option Explicit
   
   Public Sub SetNull()
   
   Dim pDispTab As IDisplayTable
   Dim pMXD As IMxDocument
   Dim pTable As ITable
   Dim pCursor As ICursor
   Dim pRow As IRow
   
   Set pMXD = ThisDocument
   Set pDispTab = pMXD.SelectedItem
   Set pTable = pDispTab.DisplayTable
   Set pCursor = pTable.Search(Nothing, False)
   Set pRow = pCursor.NextRow
   Do While Not pRow Is Nothing
   'enter the name of the field below
   pRow.Value(pTable.Fields.FindField("FieldName")) = Null 
   pRow.Store
   Set pRow = pCursor.NextRow
   Loop
   
   End Sub

   
   
5. Close the Visual Basic Editor.
6. Start an edit session in the Editor toolbar by selecting Editor > Start editing.
7. Run the code.
   
   
   A. Click Tools > Macros > Macros to display the Macros dialog box.
   B. Select a macro and click Run.