While trying to create user in Oracle Database 18c Express Edition I kept getting an “ORA-65096: invalid common user or role name” error, which didn’t make sense to me so after validating my command, that I was signed in as an admin user, and determining that my “CREATE USER” was formatted correctly. I did some additional research and determined that in the hidden parameter “_ORACLE_SCRIPT” needed to be set to “True” starting with the Oracle Version 12c and higher.
Setting the “_ORACLE_SCRIPT” values
To set the “_ORACLE_SCRIPT” hidden variable to “True” you need to run an “Alter” command. Then you will be able to create the desired user and run your grants commands as usual.
Alter SQL Command
alter session set “_oracle_script”=true;