Erreur execution 1004

Bonjour,

J'ai un problème lors de la constitution d'une macro.
Mon fichier contient un onglet par mois contenant des informations salariales (nom, prenom, type de contrat, salaires brut, heures travaillées etc...) et j'aimerais copier coller chaque mois, dans un autre onglet "synthèse", les colonnes correspondantes au nom, prénom et type de contrat et supprimer les doublons.
Cependant, quand je veux exécuter ma macro, le message d'erreur "erreur execution 1004" apparait.
Je vous mets la macro sous VBA.

Sub MAJ()
'
' MAJ Macro
'

'
ActiveWindow.ScrollWorkbookTabs Position:=xlFirst
Sheets("Janvier").Select
Range("A2:C2").Select
Range(Selection, Selection.End(xlDown)).Select
Selection.Copy
Application.CutCopyMode = False
Range("A2:C75").Select
Selection.Copy
Sheets("Suivi Mensuel").Select
ActiveSheet.Paste
Sheets("Fevrier").Select
ActiveWindow.SmallScroll Down:=-12
Range("A2:C75").Select
Application.CutCopyMode = False
Selection.Copy
Sheets("Suivi Mensuel").Select
ActiveWindow.SmallScroll Down:=60
Range("A77").Select
ActiveSheet.Paste
ActiveWindow.SmallScroll Down:=72
Sheets("Mars").Select
ActiveWindow.SmallScroll Down:=-9
Range("A2:C75").Select
Application.CutCopyMode = False
Selection.Copy
Sheets("Suivi Mensuel").Select
Range("Tableau2[#Totals,[Nom]]").Select
ActiveSheet.Paste
ActiveWindow.SmallScroll Down:=81
Sheets("Avril").Select
ActiveWindow.SmallScroll Down:=-9
Range("A2:C75").Select
Application.CutCopyMode = False
Selection.Copy
Sheets("Suivi Mensuel").Select
Range("Tableau2[#Totals,[Nom]]").Select
ActiveSheet.Paste
ActiveWindow.SmallScroll Down:=66
Range("Tableau2[#Totals,[Nom]]").Select
Sheets("Mai").Select
Range("A2:C75").Select
Application.CutCopyMode = False
Selection.Copy
Sheets("Suivi Mensuel").Select
ActiveSheet.Paste
Selection.End(xlDown).Select
Range("A358").Select
Sheets("Juin").Select
Range("A2:C75").Select
Application.CutCopyMode = False
Selection.Copy
Sheets("Suivi Mensuel").Select
ActiveSheet.Paste
Selection.End(xlDown).Select
Range("A426").Select
Sheets("Juillet").Select
ActiveWindow.SmallScroll Down:=-6
Range("A2:C75").Select
Application.CutCopyMode = False
Selection.Copy
Sheets("Suivi Mensuel").Select
ActiveSheet.Paste
ActiveWindow.SmallScroll Down:=27
Selection.End(xlDown).Select
ActiveWindow.SmallScroll Down:=6
Range("A491").Select
Sheets("Aout").Select
Range("A2:C75").Select
Application.CutCopyMode = False
Selection.Copy
Sheets("Suivi Mensuel").Select
ActiveSheet.Paste
ActiveWindow.SmallScroll Down:=78
Sheets("Septembre").Select
Range("A2:C75").Select
Application.CutCopyMode = False
Selection.Copy
Sheets("Suivi Mensuel").Select
Range("Tableau2[#Totals,[Nom]]").Select
ActiveSheet.Paste
Selection.End(xlDown).Select
Sheets("Octobre").Select
Range("A2:C75").Select
Application.CutCopyMode = False
Selection.Copy
Sheets("Suivi Mensuel").Select
ActiveSheet.Paste
Selection.End(xlDown).Select
Sheets("Novembre").Select
Range("A2:C75").Select
Application.CutCopyMode = False
Selection.Copy
Sheets("Suivi Mensuel").Select
ActiveSheet.Paste
Selection.End(xlDown).Select
Sheets("Decembre").Select
Range("A2:C75").Select
Application.CutCopyMode = False
Selection.Copy
Sheets("Suivi Mensuel").Select
ActiveSheet.Paste
Application.CutCopyMode = False
Selection.End(xlDown).Select
Range("A860:C860").Select
Range(Selection, Selection.End(xlUp)).Select
Range(Selection, Selection.End(xlUp)).Select
Range("A298:C860").Select
Range("A860").Activate
Range(Selection, Selection.End(xlUp)).Select
Range(Selection, Selection.End(xlUp)).Select
Range(Selection, Selection.End(xlUp)).Select
Range(Selection, Selection.End(xlUp)).Select
Range(Selection, Selection.End(xlUp)).Select
Range(Selection, Selection.End(xlUp)).Select
Range(Selection, Selection.End(xlUp)).Select
Range(Selection, Selection.End(xlUp)).Select
Range(Selection, Selection.End(xlUp)).Select
Range("Tableau2[[Nom]:[Natureducontrat]]").Select
Range("A860").Activate
ActiveSheet.Range("Suivi Mensuel#Tout").RemoveDuplicates Columns:=Array(1, 2, 3), _
Header:=xlYes
ActiveWindow.ScrollRow = 842
ActiveWindow.ScrollRow = 839
ActiveWindow.ScrollRow = 836
ActiveWindow.ScrollRow = 834
ActiveWindow.ScrollRow = 831
ActiveWindow.ScrollRow = 825
ActiveWindow.ScrollRow = 820
ActiveWindow.ScrollRow = 814
ActiveWindow.ScrollRow = 803
ActiveWindow.ScrollRow = 795
ActiveWindow.ScrollRow = 779
ActiveWindow.ScrollRow = 767
ActiveWindow.ScrollRow = 754
ActiveWindow.ScrollRow = 734
ActiveWindow.ScrollRow = 712
ActiveWindow.ScrollRow = 685
ActiveWindow.ScrollRow = 663
ActiveWindow.ScrollRow = 643
ActiveWindow.ScrollRow = 624
ActiveWindow.ScrollRow = 596
ActiveWindow.ScrollRow = 572
ActiveWindow.ScrollRow = 544
ActiveWindow.ScrollRow = 522
ActiveWindow.ScrollRow = 491
ActiveWindow.ScrollRow = 467
ActiveWindow.ScrollRow = 445
ActiveWindow.ScrollRow = 425
ActiveWindow.ScrollRow = 406
ActiveWindow.ScrollRow = 389
ActiveWindow.ScrollRow = 376
ActiveWindow.ScrollRow = 362
ActiveWindow.ScrollRow = 354
ActiveWindow.ScrollRow = 340
ActiveWindow.ScrollRow = 331
ActiveWindow.ScrollRow = 323
ActiveWindow.ScrollRow = 315
ActiveWindow.ScrollRow = 307
ActiveWindow.ScrollRow = 293
ActiveWindow.ScrollRow = 282
ActiveWindow.ScrollRow = 273
ActiveWindow.ScrollRow = 262
ActiveWindow.ScrollRow = 251
ActiveWindow.ScrollRow = 218
ActiveWindow.ScrollRow = 202
ActiveWindow.ScrollRow = 188
ActiveWindow.ScrollRow = 169
ActiveWindow.ScrollRow = 149
ActiveWindow.ScrollRow = 130
ActiveWindow.ScrollRow = 111
ActiveWindow.ScrollRow = 91
ActiveWindow.ScrollRow = 80
ActiveWindow.ScrollRow = 72
ActiveWindow.ScrollRow = 64
ActiveWindow.ScrollRow = 55
ActiveWindow.ScrollRow = 47
ActiveWindow.ScrollRow = 44
ActiveWindow.ScrollRow = 36
ActiveWindow.ScrollRow = 31
ActiveWindow.ScrollRow = 25
ActiveWindow.ScrollRow = 20
ActiveWindow.ScrollRow = 17
ActiveWindow.ScrollRow = 14
ActiveWindow.ScrollRow = 11
ActiveWindow.ScrollRow = 9
ActiveWindow.ScrollRow = 11
ActiveWindow.ScrollRow = 14
ActiveWindow.ScrollRow = 17
ActiveWindow.ScrollRow = 20
ActiveWindow.ScrollRow = 22
ActiveWindow.ScrollRow = 20
ActiveWindow.ScrollRow = 17
ActiveWindow.ScrollRow = 14
ActiveWindow.ScrollRow = 11
ActiveWindow.ScrollRow = 9
ActiveWindow.ScrollRow = 6
ActiveWindow.ScrollRow = 3
End Sub

Merci d'avance pour votre aide.