Can’t open CHM file or CHM topics are blank

Issue:
After opening a CHM documentation file, a topic may not appear when you click a link from the Table of Contents. Also, when you try to use a Universal Naming Convention (UNC) path to open a .CHM file that exists on a network shared folder, topics in the .chm file may not appear.

Reason:
You are using Microsoft Windows XP and have installed Security Update 896358 from Microsoft, which prevents the features of some web applications to work properly.

Solution:
On Windows XP (with the security update applied) you can also simply right-click on the CHM file, select Properties, and click on the “Unblock” button. Click “Apply” and the content should be visible.

This will only work on local files.