Missing Autodesk help files (chm) – Solved

Ok, this isn’t a strictly Autodesk issue, but I started running into it a bit when trying to access some readme files that were posted on the Autodesk site. For example, you’ll notice that when you look at the readme files for service packs, you’ll see that Autodesk is now fond of posting them as CHM (compiled HTML help) files.

Autodesk CHM file

It seems like a recent development, but now, whenever I try to view these CHM files, I get the following screen:

Navigation to the webpage was canceled - CHM

After experimenting (and grumbling) a bit, I figured out what was going on. Apparently, these CHM files, being an html type file and all, can be used to run malicious code.  Microsoft, in an attempt to seal up some of these security holes, has issued updates that prevent CHM files from other computers from running.  Here’s how to tell Windows that it’s OK to view this new CHM file (provided you can trust where you got it from — In this case it came right off the Autodesk website, so I’m comfortable running it.)

1. Download the CHM and save it somewhere you can easily access it.
2. Right-click the file and go into Properties. Notice the information at the bottom of the dialog:

Unblock CHM file

3.  Just click the Unblock button. You’ll see that the message goes away.
4. Double click the file to open it. There you go!

Viewing a CHM file

I hope this quick and easy tip saves you some of the frustration I encountered!