When you open CHM from network location and try to open any topic, you get "Action canceled" error page.


The HTML Help viewer has canceled the display of the help file due to security restrictions. This will happen with all HTML Help files that you open over a network connection (note, that local HTML Help files will not be affected). This behavior is caused by Windows security update 896358, see for more details.


Place the CHM documentation on local drive.

Use some workarounds mentioned at

Use free utility HHReg which fixes this new limitation by explicitly registering the help file in the Windows registry. You can get it from You can call Hhreg.exe directly from the template to register CHM on your computer. Open your CHM template in text editor and find a line containing call to hhc.exe in $vbdoc-exec-after$ macro. It ends like:
Add call to Hhreg.exe somewhere after it. If you have installed Hhreg.exe to c:\myfolder then it should be as follows:
@"c:\myfolder\hhreg.exe" /s "$OUTPUT-PATH$\$PROJECT-NAME$.chm"

See Also