Generated Help File doesn't display Topics

So, you've built your shiny new Help Builder CHM file and ship it off to your customers. Maybe you're sending it the CHM file or a Zip file containing the help file to your customers via email or send them a link for downloading the help file or an application that contains the CHM file.

Unfortunately, if the download came off the Web and didn't run through an installer your customers may see the following when they open the help file:

The problem is one of Windows Security which recognizes that the CHM file was downloaded off the Internet and so could potentially be a security threat.

Luckily there's a fairly easy solution to this problem for the user:

• Find the CHM file in Windows Explorer
• Right click and select Properties
• On the General tab find and click the Unblock button

Here's what the dialog looks like:

Once you've unblocked the file you can then access the CHM file properly.

What's the Problem

The problem here is a Windows security issue which tries to block potential issues with running the CHM file which is essentially a Web Browser control wrapped into the CHM viewing application. Since the application runs on the local machine there's potential for security hacks that allow loading of ActiveX controls and other issues. Microsoft's answer is to block the files even though the local machine security zone long ago stopped allowing ActiveX controls to run without special authorization.

Avoiding the Problem: Use an Installer for your Application and Help File

The best way to sidestep this issue is to use a full installer for your application. If you are installing an application that includes a help file, and you package the help file with your installation the help file will be installed alongside your application and get the proper security attributes installed. Basically the installer is trusted and so all files from the installer package are trusted as well.

For more info on this topic you can also check out our blog post on this topic:

• <a href='http://www.west-wind.com/weblog/posts/2012/Jan/11/Problems-with-opening-CHM-Help-files-from-Network-or-Internet" target="top">Problems with opening CHM Help files from Network or Internet