First look for a file located under $ORACLE_HOME/NETWORK/LISTENER.LOG. This should provide with more info on why the listener fails to start up.
The listener can be restarted from DOS prompt using the following steps:
cd to $ORACLE_HOME\bin directory and run LSNRCTL*.exe, then from LSNRCTL> prompt issue START command like the following
LSNRCTL> start
Related Issues/Questions:
nhStartDb failed with unable to start TNS Listener
How to start TNS Listener on a Microsoft Windows system
Error from nhStartDb or startup: "ORA-12560: TNS:protocol adapter error SVRMGR> Password: ORA-12560: TNS:protocol adapter error"
Oracle listener fails to start up
Problem Environment:
eHealth 5.x
Oracle
(Legacy KB ID CNC TS16176 )