Oracle: How to solve ORA-28040
This is how to solve connection error ORA-28040
When you move to a new database system, many errors can occour - no matter how much you prepare.
An error that can be solved quiet easily is ORA-28040, which says "No matching authentication protocol". It means that your database is of a newer release than your client (no matter if Oracle Client or JDBC client). Because of that, communication and authentication protocols have changed.
To solve this problem, just add this line
SQLNET.ALLOWED_LOGON_VERSION_SERVER = 8on database server to $ORACLE_HOME/network/admin/sqlnet.ora in your database home (not in your Grid Infrastructure home!).
Without having to restart anything, you can try again to connect your application.
Easy 😄
But keep in mind that you still have a time bomb - either your driver is outdated, oy your software. And maybe, this parameter will not work any more - either after a specific Release Update, or after a new Release. So try to update your components.