Hello,
It seems that Link does not work.
However, I was Successful in finding the correct link.
https://www-secure.symantec.com/connect/forums/blank-error-message-when-searching-unmanaged-clients
(Please Let me know if this is the exact link you were talking about?)
Could you please Let us know if the SEPM 11.0.6005 installed on what Operating System?
Ports required by Find Unmanaged Computers:
Either TCP port 139 or 445 need to be open for the installation package to be delivered to the remote computer. If UDP port 137 is closed, the Endpoint Protection Manager will not be able to list the hostname of the computer during the initial scan. (Though deployment can still be carried out by manually entering the IP address of the prospective client.)
Check this:
About the Find Unmanaged Computers function in Symantec Endpoint Protection Manager
Also, check:
Deploying client software using "Find Unmanaged Computers" in Symantec Endpoint Protection Manager (SEPM) fails without error messages
&
Unable to install SEP client on Windows 7 from Windows 2008 R2 server by using the Find Unmanaged Computers in a Domain.
Hope this helps!!!