Shared File Causing 1004 Error

Hi,

I'm wondering if anyone might know, why my code would hit a run time error on a shared file? It works fine unshared. This is on a ActivateSheet Worksheet Event, Code is housed in a Module and called when activated

Private Sub Worksheet_Activate()
    Call RatingsValidations
End Sub

Sub RatingsValidations()
    Dim i As Long
    Dim c As Long
    
    Dim MDPRSelTemp
    Dim MDPRSel() As Variant
    Dim MDPRString As Variant
    
    Dim MRSelTemp
    Dim MRSel() As Variant
    Dim MRString As Variant
    
    Dim MWARFSelTemp
    Dim MWARFSel() As Variant
    Dim MWARFString As Variant
        
    Dim SPSelTemp
    Dim SPSel() As Variant
    Dim SPString As Variant
    
    Dim FitchSelTemp
    Dim FitchSel() As Variant
    Dim FitchString As Variant
    
    MDPRSelTemp = WorksheetFunction.Transpose([NotchingSelectionMDPR])
    MRSelTemp = WorksheetFunction.Transpose([NotchingSelectionMR])
    MWARFSelTemp = WorksheetFunction.Transpose([NotchingSelectionMWARF])
    SPSelTemp = WorksheetFunction.Transpose([NotchingSelectionSP])
    FitchSelTemp = WorksheetFunction.Transpose([NotchingSelectionFitch])
    
    c = 0
    For i = 1 To UBound(MDPRSelTemp)
        If MDPRSelTemp(i) <> False Then
            ReDim Preserve MDPRSel(c)
            MDPRSel(c) = MDPRSelTemp(i)
            c = c + 1
        End If
    Next
        
    c = 0
    For i = 1 To UBound(MRSelTemp)
        If MRSelTemp(i) <> False Then
            ReDim Preserve MRSel(c)
            MRSel(c) = MRSelTemp(i)
            c = c + 1
        End If
    Next
        
    c = 0
    For i = 1 To UBound(MWARFSelTemp)
        If MWARFSelTemp(i) <> False Then
            ReDim Preserve MWARFSel(c)
            MWARFSel(c) = MWARFSelTemp(i)
            c = c + 1
        End If
    Next
    
    c = 0
    For i = 1 To UBound(SPSelTemp)
        If SPSelTemp(i) <> False Then
            ReDim Preserve SPSel(c)
            SPSel(c) = SPSelTemp(i)
            c = c + 1
        End If
    Next
    
    c = 0
    For i = 1 To UBound(SPSelTemp)
        If SPSelTemp(i) <> False Then
            ReDim Preserve SPSel(c)
            SPSel(c) = SPSelTemp(i)
            c = c + 1
        End If
    Next
    

    MDPRString = Join(MDPRSel, ",")
    MRString = Join(MRSel, ",")
    MWARFString = Join(MWARFSel, ",")
    SPString = Join(SPSel, ",")
    FitchString = Join(FitchSel, ",")
    
    
    Sheet4.[ValidationMDPRSelection].Validation.Delete
    Sheet4.[ValidationMRSelection].Validation.Delete
    Sheet4.[ValidationMWARFSelection].Validation.Delete
    Sheet4.[ValidationSPSelection].Validation.Delete
    
    If MDPRString = "" Then
    Else
        Sheet4.[ValidationMDPRSelection].Validation.Add Type:=xlValidateList, Formula1:=MDPRString
    End If
        
    If MRString = "" Then
    Else
        Sheet4.[ValidationMRSelection].Validation.Add Type:=xlValidateList, Formula1:=MRString
    End If
    
    If MWARFString = "" Then
    Else
        Sheet4.[ValidationMWARFSelection].Validation.Add Type:=xlValidateList, Formula1:=MWARFString
    End If
    
    If SPString = "" Then
    Else
        Sheet4.[ValidationSPSelection].Validation.Add Type:=xlValidateList, Formula1:=SPString
    End If
   
'STATUS
    Dim MDPRStatusTemp
    Dim MDPRStatus() As Variant
    Dim MDPRString2 As Variant
    
    Dim MRStatusTemp
    Dim MRStatus() As Variant
    Dim MRString2 As Variant
    
    Dim MWARFStatusTemp
    Dim MWARFStatus() As Variant
    Dim MWARFString2 As Variant
        
    Dim SPStatusTemp
    Dim SPStatus() As Variant
    Dim SPString2 As Variant
    
    Dim FitchStatusTemp
    Dim FitchStatus() As Variant
    Dim FitchString2 As Variant
    
    MDPRStatusTemp = WorksheetFunction.Transpose([NotchStatusMDPR])
    MRStatusTemp = WorksheetFunction.Transpose([NotchStatusMR])
    MWARFStatusTemp = WorksheetFunction.Transpose([NotchStatusMWARF])
    SPStatusTemp = WorksheetFunction.Transpose([NotchStatusSP])
    FitchStatusTemp = WorksheetFunction.Transpose([NotchStatusFitch])
    
    c = 0
    For i = 1 To UBound(MDPRStatusTemp)
        If MDPRStatusTemp(i) <> False Then
            ReDim Preserve MDPRStatus(c)
            MDPRStatus(c) = MDPRStatusTemp(i)
            c = c + 1
        End If
    Next
        
    c = 0
    For i = 1 To UBound(MRStatusTemp)
        If MRStatusTemp(i) <> False Then
            ReDim Preserve MRStatus(c)
            MRStatus(c) = MRStatusTemp(i)
            c = c + 1
        End If
    Next
        
    c = 0
    For i = 1 To UBound(MWARFStatusTemp)
        If MWARFStatusTemp(i) <> False Then
            ReDim Preserve MWARFStatus(c)
            MWARFStatus(c) = MWARFStatusTemp(i)
            c = c + 1
        End If
    Next
    
    c = 0
    For i = 1 To UBound(SPStatusTemp)
        If SPStatusTemp(i) <> False Then
            ReDim Preserve SPStatus(c)
            SPStatus(c) = SPStatusTemp(i)
            c = c + 1
        End If
    Next
    
    c = 0
    For i = 1 To UBound(SPStatusTemp)
        If SPStatusTemp(i) <> False Then
            ReDim Preserve SPStatus(c)
            SPStatus(c) = SPStatusTemp(i)
            c = c + 1
        End If
    Next
    
    MDPRString2 = Join(MDPRStatus, ",")
    MRString2 = Join(MRStatus, ",")
    MWARFString2 = Join(MWARFStatus, ",")
    SPString2 = Join(SPStatus, ",")
    FitchString2 = Join(FitchStatus, ",")
    
    
    Sheet4.[ValidationMDPRStatus].Validation.Delete
    Sheet4.[ValidationMRStatus].Validation.Delete
    Sheet4.[ValidationMWARFStatus].Validation.Delete
    Sheet4.[ValidationSPStatus].Validation.Delete
    
    If MDPRString2 = "" Then
    Else
        Sheet4.[ValidationMDPRStatus].Validation.Add Type:=xlValidateList, Formula1:=MDPRString2
    End If
    
    If MRString2 = "" Then
    Else
        Sheet4.[ValidationMRStatus].Validation.Add Type:=xlValidateList, Formula1:=MRString2
    End If
    
    If MWARFString2 = "" Then
    Else
        Sheet4.[ValidationMWARFStatus].Validation.Add Type:=xlValidateList, Formula1:=MWARFString2
    End If
    
    If SPString2 = "" Then
    Else
        Sheet4.[ValidationSPStatus].Validation.Add Type:=xlValidateList, Formula1:=SPString2
    End If


End Sub

Thanks for your help in advance