The username or password for the connection pool named |apex||, are invalid, expired, or the account is locked

 1. Execute the following command from SQL Plus as the SYS user: 

Conn sys/Pass@xe as sysdba  (connect as container if 12c then ALTER SESSION SET container = CDB$ROOT;)

Alter user ords_public_user identified by xxxx;
ALTER USER ORDS_PUBLIC_USER ACCOUNT UNLOCK;

Connect as PDB

Conn sys/Pass@xepdb1 as sysdba (if 12c ALTER SESSION SET container = PDB1;)

Alter user APEX_PUBLIC_USER identified by xxxx;
Alter user APEX_REST_PUBLIC_USER identified by xxxx;
Alter user APEX_LISTENER identified by xxxx;

2. Unlock the users:

ALTER USER APEX_PUBLIC_USER ACCOUNT UNLOCK;
ALTER USER APEX_REST_PUBLIC_USER ACCOUNT UNLOCK;
ALTER USER APEX_LISTENER ACCOUNT UNLOCK;
ALTER USER ORDS_PUBLIC_USER ACCOUNT UNLOCK;

3. Now create a profile for the APEX related users:

Create profile apex_public_profile limit password_life_time unlimited;

4. Assign the profile to the APEX users:

alter user apex_public_user profile apex_public_profile;
alter user apex_rest_public_user profile apex_public_profile;
alter user apex_listener profile apex_public_profile;
alter user ords_public_user profile apex_public_profile;

5. Restart Tomcat /ORDS