Don't call a folder C# if you have a compiled HTML help (chm) file in there

If you place a .chm (compiled html help file) into a directory with a # in the path then the contents of the .chm file will not be displayed.


Instead the following will appear:



Rename the folder to remove the # and then try again...

 

This is also covered in the MSDN BUG: No Text or Access Violation Error When Reading a Help File