Occasionally people install (or run) WDS from a network drive/share. The HTML help file viewer of Windows, however, is configured so that it restricts all HTML content over the network, including these types of resources. Consequently the viewer will show a help file window with some weired error message that depends on your system language.
To fix this issue, the only known method is to move the help file (and hence the program) to a non-network location.
// Oliver