Run-Time error 1004 when trying to run Macro

[Matt2014]

Hi all, I'm getting the error 1004 whilst running this macro. It was working fine earlier, any advice would be much appreciated.

Sub DateFormat()

' converts dates from dd.mm.yy format to dd/mm/yy format

Dim LastRow As Integer

 jLastRow = Sheets("Data").UsedRange.Rows.Count
 
    Columns("J:J").Select
    
    Selection.Insert Shift:=xlToRight, CopyOrigin:=xlFormatFromLeftOrAbove
    Selection.Insert Shift:=xlToRight, CopyOrigin:=xlFormatFromLeftOrAbove
    
    Range("J1").Select
    ActiveCell.FormulaR1C1 = "=REPLACE(RC[-1],3,1,""/"")"
    Selection.AutoFill Destination:=Range(Cells(1, 10), Cells(jLastRow, 10))
    
    Range("K1").Select
    ActiveCell.FormulaR1C1 = "=REPLACE(RC[-1],6,1,""/"")"
    Selection.AutoFill Destination:=Range(Cells(1, 11), Cells(jLastRow, 11))

Call GetDays

End Sub

The error occurs on the line: "Selection.AutoFill Destination:=Range(Cells(1, 10), Cells(jLastRow, 10))"




Thanks,

Matt