ORA-00119: invalid specification for system parameter REMOTE_LISTENER ORA-00132: syntax error or unresolved network name 'example-scan:1521'

This silly error took lot of time to get fixed.

SQL> startup nomount
ORA-00119: invalid specification for system parameter REMOTE_LISTENER
ORA-00132: syntax error or unresolved network name 'example-scan:1521'

11gR2 requires remote_listener to be set to <scan_name:port> which was set properly

Another strange requirement is that the DIRECTORY_PATH PARAMETER IN sqlnet.ora should have EZCONNECT as one of values and mistakenly it was modified and had only TNSNAMES. 

Once added EZCONNECT, database started up properly

NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)