"Action canceled" error messages when opening the HELP files

PROBLEM
When opening the compiled html CHM file, an error message pops up:
"Navigation to the webpage was canceled"

SOLUTION
The issue is caused by the Microsoft security update MS05-026 from June 14, 2005 as it updates the HTML Help Control (the CHM viewer) to version 5.2.3790.315 (to check the CHM version, right-click on the viewer button on the taskbar and choose "About HTML Help"). The known issues of this security update are documented in Microsoft Knowledge Base Article 896358.

When using the compiled HTML help files you should have in mind these important notes:

1. In the File Download dialog box, click Save, and then choose where you want to save the CHM file.

Note: Save is the only available option in Mozilla Firefox browser. If you are using Mozilla Firefox, when you download the file locally you can skip the steps below and open the file.

In order to open the CHM file, use one of the following methods (for IE users):

Method 1

1. Double-click the CHM file.

2. In the Open File-Security Warning dialog box, click to clear the Always ask before opening this file check box.

3. Click Open.

Method 2

1. Right-click the CHM file, and then click Properties.

2. Click Unblock.

3. Double-click the CHM file to open the file.