May be the workbook is protected.

Go to Revew tab | protect workbook | any tick is there for protect
structure and windows | then its protected.

If its not protected then, check the sheet named "exporteren data" is
already exist.

Sub makesheet()
Sheets.add.name = "exporteren data"
end sub

On May 1, 5:19*pm, Willem wrote:
Hi,

We recently upgraded from Office 2003 to Office 2007. In some macro's errors
start occurring, e.g. the Excel macro that adds an extra sheet to a workbook,
and always worked flawless, now stops running.
Also i cannot add a worksheet manually; I can see the tab but it is disabled.
The workbook consists of several (protected) worksheets.
The macro is very simple:
Sub MakeSheet()
' * *Application.ScreenUpdating = False
* * Sheets.Add
* * ActiveSheet.Name = "exporteren data"
End Sub

What can be the problem?