Tracing

If you use the -terp command line option to enable tracing, a message is sent to the errorlog every time the user invokes help.

Error Handling

If a help ID does not match any help topic defined in the current help library, Windows Help displays a message saying that "This program cannot display the webpage", followed by likely causes. This can occur when the user requests help for any object, requests extended help, or requests keys help. No error is sent to the errorlog.

It is not an error if the Windows Help system has not been initialized (meaning there is no help library environment declaration in the ESL application) and the user requests help.