Highlight tool is grayed out

[Jim04]

I am trying to highlight text in a PDF document.  I click the Comment icon but all the tools including the highlighter are grayed out.

Using Acrobat Pro DC version 2021.001

[Abambo]

Please tell more about the security settings of the file.

[Jim04]

This is a screenshot of the securities settings.

 

[Bernd Alheit]

In this document adding of comments are not allowed.