Just a typo alert.
You have "target.cell.count". You meant "target.cells.count".
But if you're changing something in a worksheet_change event, it's usually best
to disable events while you do your change. Then the change you code makes
doesn't cause the event to fire again.
Your routine slightly modified:
Option Explicit
Private Sub Worksheet_Change(ByVal Target As Range)
'Only one cell
If Target.Cells.Count > 1 Then Exit Sub
'Only column N
If Intersect(Target, Me.Range("N:N")) Is Nothing Then Exit Sub
On Error GoTo errHandler:
'Work on entire column, changing same row column J value
If LCase(Target.Value) = LCase("Removed") Then
Application.EnableEvents = False
Me.Cells(Target.Row, "J").Value = 0
End If
errHandler:
Application.EnableEvents = True
End Sub
(I also changed target.value to lcase(target.value)--just in case the user types
removed or REMOVED or some variation.)