Splunk Cloud - error while installing universal forwarder credentials. No users exist. Please set up a user.

[vishalkohli]

I am following steps mentioned in
http://docs.splunk.com/Documentation/SplunkCloud/7.0.2/User/ForwardDataToSplunkCloudFromLinux

while executing following command
/opt/splunkforwarder/bin/splunk install app /usr/src/splunkclouduf.spl -auth admin:changeme

I get message: "No users exist. Please set up a user."

I get the same message when editing the password
splunk edit user admin -password mynewpassword -auth admin:changeme

Please let me know if anyone has faced similar problem.

Regards,
Vishal