Hi Herbert;
Support for the new EXCEL SaveAs ( ) was added to PB quite a while ago when .Net 3.0 was the minimum requirement. However today, both PB Classic and PB.Net 12.5.x are based on .NET 4.0 - thus, the Excel SaveAs ( ) requirement gets trumped by the newer PB requirement.
HTH
Regards ...Chris
PS: Note: PB 12.5.x does not support .NET 4.5