The SaveCopyAs command doesn't have a file format argument. It only has a FileName argument.

An alternate solution is to copy all the sheets to a new workbook then use SaveAs on the new workbook.

ActiveWorkbook.Sheets.Copy  'copy all sheets to a new workbook
ActiveWorkbook.SaveAs FileName:=Path & FileName, FileFormat:=xlOpenXMLWorkbook, CreateBackup:=False 'Save copied workbook
ActiveWorkbook.Close False 'close the saved copy