Excel export error

Hei,

I am encountering what seems to be a recurring problem: 

when using the excel read (legacy), i get this error:

            {0;0}
0. System.Runtime.InteropServices.COMException (0x800401E3): Vorgang nicht verfügbar. (Ausnahme von HRESULT: 0x800401E3 (MK_E_UNAVAILABLE))
   bei System.Runtime.InteropServices.Marshal.GetActiveObject(Guid& rclsid, IntPtr reserved, Object& ppunk)
   bei System.Runtime.InteropServices.Marshal.GetActiveObject(String progID)
   bei LunchBox.WF_ExcelRead.SolveInstance(IGH_DataAccess DA)

any ideas?

thank you!!