Ora 01017 Invalid Username Password; with correct data I am new to oracle (enterprise:12.2.0.1) and after installation I logged in with connect sys as sysdba.
I also created a new user with:
 alter session set &quot;_ORACLE_SCRIPT&quot;=true;
 create user dummy identified by dummy;
 GRANT ALL PRIVILEGES TO dummy;

Everything went successful until now, but when I tried to log in with the new created user with 'connect dummy' I get the error: Ora 01017 Invalid Username Password; logon denied
After resetting the password 10 times and creating 8 new users, I am nearly 100% sure, the password and username is correct.
I read, that this problem can also appear because of the tnsnames.ora file, but I don't try to connect with TNS, so I would rule this case.
After many hours, I would now be happy, if I can get here a simple step-by-step solution and explanation.
Thank you very much and greetings from Germany.
I reinstalled oracle and now it works fine.
My guess with tnsnames.ora was totally wrong and also think there was the error!