Oracle Error ORA-01096: program version (string) incompatible with instance (string)

Oracle Error Message

ORA-01096: program version (string) incompatible with instance (string)

Reason for the Error

A program is trying to connect to an instance using a different version of code than the database was started with. This is not allowed.

Solution

Either relink the program with the same version as the database or restart the database using the old version of code.