ORA-12560: TNS:protocol adaptor error - Oracle 19c

You can read this guide where it shows two possible solutions

https://aflorestorres.com/2020/09/27/solucionar-error-oracle-tnserror-del-adaptador-de-protocolo-oracle-18c-xe/

 

However if you have problem yet to connect SQLPLUS due to OracleServiceORCL doesn't exists in  Windows Services, so the best solution is open the window CMD and execute the follow command:

C:\> ORADIM -NEW -SID ORCL

 

Then, just go to Command prompt

1. Set Oracle SID C:>set oracle_sid=ORCL

2. Now run Net start command. C:>net start oracleserviceORCL

 

Or when you set value to enviroment variable ORACLE_SID you must type ORCL instead XE, and you will see how it works.