Oracle Solution for Error ora-04099

ORA-04099: trigger 'string' is valid but not stored in compiled form

What triggered the Error:

A trigger was attempted to be retrieved for execution and was found to be valid, but not stored. This may mean the an upgrade was done improperly from a non-stored trigger release.

What should we do to fix it:

Alter compile the trigger to create the trigger in stored form. Also, you may want to review that a proper upgrade was done.