Yesterday I installed Oracle 12c database on my PC and configured it like in this guide. Then I created two connections in SQL Developer: first one with a system user, then I created another user and made the second connection with that user. I managed to establish both connections. I even made some sample table using the second one. Well, everything worked great until I restarted my PC. After that I tried to establish a connection, but no luck with either of them. The following error message was displayed:
I simply don't get it. I restarted my PC normally, restarted Oracle services, also did a db shutdown and startup... nothing. Running
select instance_name, status, database_status from v$instance; from SQL Plus says
Any suggestion? I'm simply running out of options...