Remove duplicates from range not removing anything - excel

Question

The following code does not remove any duplicate, what am I missing ?
LastColumn = 10
ws.Range(ws.Cells(1, ws.Range("AY1").Column + LastColumn - 1).Address(), ws.Cells(1, "AY").Address()).RemoveDuplicates
I replaced RemoveDuplicates by .Select to check if the excepted range was selected and it was.

Answer 1

Please, test the next way. It will keep only the first occurrences and replace with empty cells the next duplicates. The processed result is returned on the next (second) row (for testing reason). If it works as you need, you can simple replace ws.Range("AY2").Resize with ws.Range("AY1").Resize:
Sub removeDuplicatesOnRow()
Dim ws As Worksheet, lastColumn As Long, arrCol, i As Long
lastColumn = 10
Set ws = ActiveSheet
arrCol = ws.Range(ws.cells(1, ws.Range("AY1").Column + lastColumn - 1), ws.cells(1, "AY")).value
arrCol = removeDuplKeepEmpty(arrCol)
ws.Range("AY2").Resize(1, UBound(arrCol, 2)).value = arrCol
End Sub
Function removeDuplKeepEmpty(arr) As Variant
Dim ar, dict As Object, i As Long
ReDim ar(1 To 1, 1 To UBound(arr, 2))
Set dict = CreateObject("Scripting.Dictionary")
For i = 1 To UBound(arr, 2)
If Not dict.Exists(arr(1, i)) Then
dict(arr(1, i)) = 1
ar(1, i) = arr(1, i)
Else
ar(1, i) = ""
End If
Next i
removeDuplKeepEmpty = ar
End Function
If you need to keep only unique values/strings in consecutive columns, the function can be adapted to do it. You did not answer my clarification question on the issue and I assumed that you do not want ruining the columns below the processed row. But, if my supposition is wrong, I can post a code doing the other way...

Answer 2

Remove Row Duplicates
Option Explicit
Sub RemoveRowDuplicates()
Dim ws As Worksheet: Set ws = ActiveSheet ' be more specific
Dim fCell As Range: Set fCell = ws.Range("AY1")
Dim lCell As Range: Set lCell = ws.Cells(1, ws.Columns.Count).End(xlToLeft)
If lCell.Column < fCell.Column Then Exit Sub ' no data in row range
Dim rg As Range: Set rg = ws.Range(fCell, lCell)
Dim cCount As Long: cCount = rg.Columns.Count
If cCount < 2 Then Exit Sub ' only one column
Dim sData As Variant: sData = rg.Value ' Source
Dim dict As Object: Set dict = CreateObject("Scripting.Dictionary")
dict.CompareMode = vbTextCompare ' ignore case i.e. 'A = a'
Dim dData As Variant: ReDim dData(1 To 1, 1 To cCount) ' Dest. (Result)
Dim sValue As Variant
Dim sc As Long
Dim dc As Long
For sc = 1 To cCount
sValue = sData(1, sc)
If Not IsError(sValue) Then ' is not an error value
If Len(sValue) > 0 Then ' is not blank
If Not dict.Exists(sValue) Then ' not found in dictionary
dict(sValue) = Empty
dc = dc + 1
dData(1, dc) = sValue
'Else ' found in dictionary
End If
'Else ' is blank
End If
'Else ' is error value
End If
Next sc
rg.Value = dData
MsgBox "Found " & dc & " unique values.", vbInformation
End Sub