[gentoo-user] KDE Help Center in Plasma 5, "help:" protocol Unknown

[gentoo-user] KDE Help Center in Plasma 5, "help:" protocol Unknown

[»Q«]

I get a message like the one below instead of any help content
whenever I try to use the KDE Help Center
(kde-plasma/khelpcenter-5.5.5).  ISTM there must be something I don't
have installed but need to, but I can't figure out what it is.  any
ideas?


The requested operation could not be completed
Cannot Initiate the help Protocol
Technical Reason: Unable to Launch Process

Details of the Request:
   URL: help:/khelpcenter/help-system-handbook.html
   Protocol: help
   Date and Time: Saturday, April 9, 2016 11:37:12 PM CDT
   Additional Information: Unable to create io-slave: klauncher said:
   Unknown protocol 'help'. Description:

The program on your computer which provides access to the help protocol
could not be started. This is usually due to technical reasons.

Possible Causes: 
  The program which provides compatibility with this
  protocol may not have been updated with your last update of KDE. This
  can cause the program to be incompatible with the current version and
  thus not start. 
  You may have encountered a bug in the program.

Possible Solutions: 
  Update your software to the latest version. Your
  distribution should provide tools to update your software.
  Contactt your appropriate computer support system, whether the system
  administrator, or technical support group for further assistance.