I'm having the same problem. I tried it in QV10 - both SR3 & SR6.
The Error Message is "Unrecognised message version."
I followed all these intructions, but still no luck.
Add the user that is executing the tool to the "QlikView Management API" Windows group. This group does not exist by default and must be created.
Change the line below in qv-user-manager.exe.config file to reflect the server address of your QlikView Management Service.
<endpoint address="http://sesth-rfn1:4799/QMS/Service" binding="basicHttpBinding"
name="BasicHttpBinding_IQMSBackend" behaviorConfiguration="ServiceKeyEndpointBehavior" />
It's recommended to schedule and run the tool from a batch file, see below for examples.