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

ERRORprogram version (string) incompatible with instance (string)
CAUSEA program is trying to connect to an instance using a different version of code than the database was started with. This is not allowed.
ACTIONEither relink the program with the same version as the database or restart the database using the old version of code.

92052Current Oracle patch set for version 7.3.3