Unable to call HTML Help from app

Our developer has been unsuccessful calling the .CHM help file within our application. He has added the new library, changed the path to the Help file, specified that he wants to use the HTML Help, and changed the call from WinHelp to HTML Help. He still gets a general error message when he tries to launch the Help, saying it cannot be opened.

What are we missing? What's the solution? Or, barring that, how about some ideas as to what the problem is? Please ignore--same message posted twice!