Listener has 0 handler for the service, 18C GI and Database.

I installed Oracle RAC 18C (GI and DB). When I tried to create a db I got a error "ORA-12516: TNS:listener could not find available handler with matching protocol stack".

I skipped this step and ended up with a database with problem I hope I could fix later.  The status of listener  shows " 0 handler for the service"

[grid@tiger2 ~]$ lsnrctl status listener_scan2

.....

Service "trac.xxx.xxx.edu" has 3 instance(s).

  Instance "trac1", status READY, has 0 handler(s) for this service...

  Instance "trac2", status READY, has 0 handler(s) for this service...

  Instance "trac3", status READY, has 0 handler(s) for this service...