Run-time error '6'

Hi guys, I have query which calculates and autofills columns, but there's a problem "run-time error 6" on 3rd row.
________________
Sub Macros()
Dim lastOne As Integer
lastOne = Worksheets(1).Cells(Rows.Count, 2).End(xlUp).Row
Range("H1").Value = "Cost1"
Range("I1").Value = "Cost2"
Range("J1").Value = "Cost3"
Range("K1").Value = "Value"
Range("K1").Select
With Selection.Font
.Color = -16776961
.TintAndShade = 0
End With
Range("H2").Select
ActiveCell.FormulaR1C1 = "=R[+1]C[-3]+RC[-3]"
Range("I2").Select
ActiveCell.FormulaR1C1 = "=R[+1]C[-3]+RC[-3]"
Range("J2").Select
ActiveCell.FormulaR1C1 = "=R[+1]C[-3]+RC[-3]"
Range("K3").Select
ActiveCell.FormulaR1C1 = "=RC[-1]-R[-1]C[-1]"
Range("H2:K2").AutoFill Destination:=Range("H2:K2" & CStr(lastOne)), Type:=xlFillDefault
End Sub
_____________________________________

When I'm trying to change 'integer' to 'long' there's another problem "Run-time error 1004, Method 'Range' of object '_Global' Failed" on 21st row.

I would be appreciative for any advice.

Your post does not comply with Rule 3 of our Forum RULES. Use code tags around code.

Posting code between [CODE]Please [url=https://www.excelforum.com/login.php]Login or Register [/url] to view this content.[/CODE] tags makes your code much easier to read and copy for testing, it also maintains VBA formatting.

Highlight your code and click the # icon at the top of your post window. More information about these and other tags can be found here



(This thread should receive no further responses until this moderation request is fulfilled, as per Forum Rule 7)