Ran into this problem when trying to add a client to satellite.
[root@localhost ~]# rhnreg_ks --serverUrl=http://192.168.11.22/XMLRPC --activationkey=75e725ba3f0420837eb212af0148243e Error Message: Could not find token '75e725ba3f0420837eb212af0148243e' Error Class Code: 60 Error Class Info: The activation token specified could not be found on the server. Please retry with a valid key.
It looks like the issue is that the key was missing some characters. The key was supposed to start with “1-” like below
[root@localhost ~]# rhnreg_ks --serverUrl=http://192.168.1.12/XMLRPC --activationkey=1-75e725ba3f0420837eb212af0148243e This system is not subscribed to any channels. RHN channel support will be disabled.