The requested documentation was not found on your computer. Normally, KDE looks for application handbooks in a location that depends on how KDE was installed on your computer. There are a number of possible reasons why it could not find the documentation you requested. The document might not exist, or it may not have been installed along with the application.
How to solve this issue:
Start by searching the KDE Documentation site for the requested documentation. If you find the documentation on that site, your distribution might ship a separate package for documentation (e.g. called kdepim-doc for all applications from the kdepim module, like KMail, Kontact, etc.). Please use the package manager of your distribution to find and install the missing documentation.
If you use a source based distribution, such as Gentoo, be sure that there are not any configuration settings (USE flags in Gentoo) that might have disabled the installation of the documentation.
If you have done that, but still get this page displayed instead of the application handbook, you probably found a bug in the KDE help system. In this case, please report this on the KDE Bug Tracker.