Method 'Union' of object '_Global failed - excel

Question

Update: I realized that I can't use union on multiple sheets.
What's the best choice that I have then?
I simply want to combine all sheets in the workbook into the first worksheet.
After I went through the existing questions, I've tried adding Set rng = nothing to clear my range, but it didn't help.
Sub Combine()
Dim J As Long
Dim Combine As Range
Dim rng As Range
'I want to start from the second sheet and go through all of them
For J = 2 To Sheets.Count
With Sheets(J)
Set rng = .Range("A1", .Range("A" & .Rows.Count).End(xlUp))
End With
For Each Cell In rng
If Combine Is Nothing Then
Set Combine = Cell.EntireRow
Else
Set Combine = Union(Combine, Cell.EntireRow)
End If
Next Cell
Set rng = Nothing
Next J
'Paste the whole union into the 1st sheet
Combine.Copy Destination:=Sheets(1).Range("A1")
End Sub
All this code gets me an error Method 'Union' of object '_Global failed
Update 2
Sub Combine2()
Dim rowcount As Long
For Each Sheet In Sheets
If Sheet.Index <> 1 Then
rowcount = Sheet.UsedRange.Rows.Count
Sheet.UsedRange.Copy Destination:=Sheets(1).Cells(Lastrow + 1, 1)
Lastrow = Lastrow + rowcount
End If
Next Sheet
End Sub
Really simple code, worked perfectly, thanks to #luuklag for leading me on this.

Answer 1

Indeed .Union method doesn't work across worksheets.
Instead, you could try looping through all your worksheets, copying the corresponding range and pasting it to the destination worksheet.
Something like the following would achieve this:
Sub test()
Dim destinationSheet As Worksheet
Dim sht As Worksheet
Dim destinationRng As Range
Dim rng As Range
Set destinationSheet = ThisWorkbook.Worksheets("Name of your worksheet")
For Each sht In ThisWorkbook.Worksheets
If sht.Name <> destinationSheet.Name Then
With sht
Set rng = .Range(.Range("A1"), .Range("A" & .Rows.Count).End(xlUp))
rng.Copy
End With
With destinationSheet
Set destinationRng = .Range("A" & .Rows.Count).End(xlUp)
If destinationRng.Address = .Range("A1").Address Then
destinationRng.PasteSpecial xlPasteValues
Else
destinationRng.Offset(1, 0).PasteSpecial xlPasteValues
End If
End With
End If
Next sht
End Sub
The code above pastes the ranges one by one, in the same column. It can be easily modified to paste the ranges in different columns, one next to the other.