ORA-00019 maximum number of session licenses exceeded

Error:
ORA-00018 maximum number of sessions exceeded

SQL> conn hr@xepdb1
Enter password:
ERROR:
ORA-00019: maximum number of session licenses exceeded


Cause:
Maximum number of licenses session value exceeded to its upper limit.

Solution:
1. Check the parameter license_max_sessions value.

SQL> show parameter license_max_sessions

NAME                     TYPE     VALUE
------------------------ -------- --------
license_max_sessions     integer  1

2. If you have more license for session, you can increase this parameter value.

ALTER SYSTEM SET license_max_sessions=500 scope=both;

Note: Not need to reboot the Database.