PDF-XChange annotation function inactive

[triple]

Hi, I install PDF Xchange Viewer from https://www.pdf-xchange.com/home/pr ... fx_viewer/
The version I select is
PDF-XChange Viewer v.2.0039 2 Sep, 2008 15.30Mb Windows 2000 & Later

however, after this installation (either as a pro or free version), I can not annotate pdf files, either in the viewer standalone software or firefox browser. A lot of functions in this version is gray and not operational, especially the comment and make up tools.

I also tried the portable version and other versions, the annotation function is always gray. I am wondering what's wrong here?
I also tried to install tools the PDF-Tools 4 v.4.0152 9 Oct, 2008 9.98Mb Windows 95 & Later, still annotation function does not work.

How can I get around this and get the annotation function for free? Thanks

[Bhikkhu Pesala]

Have a look at the security permissions in Document Properties (Control D). If commenting is "Not allowed" then the tools will be greyed out. This is not a question of the free version vs the paid for version. All commenting tools are available in the free version, and all other features too, but using the Pro features will add a watermark.

Create your own PDF document and test that.