When you are in the main list looking at all the doc, select Installing.
You will see this
Last update March 20, 2018
For instructions to install, upgrade, migrate, and start CA NetMaster NM for TCP/IP, see Install or Upgrade CA NetMaster Products in the CA
There is a link to 'Install or Upgrade CA NetMaster Products'.
Please click on that.
Now try creating a PDF.
Apparently you are not actually in the manual yet until you click on that link, so it cannot create a PDF.