1. You can change general macro settings in the Trust Center (M365). Choose Disable all macros without notification
2. You can save the file as ".xls " or ".xlsx" before with the Excel VBO "Save Workbook as". To force the format of the file, you can create a new page "Save Workbook as .xlsx" with this code stage:
Dim wb as Object = GetWorkbook(handle,workbookname)
Dim excel as Object = wb.Application
excel.DisplayAlerts = False
wb.SaveAs (filename, 51)
excel.DisplayAlerts = True
newworkbookname = wb.Name