How to fix this error that happens when I try to convert xls to pdf

Question

The warning in the picture pops up when I try to save an excel file (format: xls) into pdf using the save as function. When translated, it means "This file format is not supported by Microsoft Information Protection. You must convert the document to a supported format first."

I want to understand a few things

1. Why does Microsoft Information Protection not support this format?
2. I want to know if there's any way for me to save excel files with the format of xls (or excel 97-2003) into a pdf file without changing the format of the excel.
3. If there's no method for 2, I would like to make edits in the protection scheme so that it opens the excel file without any problem.

Answer 1

Sub ExtraerPaginasPDF()

Dim AcroApp As Object, PartDoc As Object

Dim