How to fix the Oracle error PLS-00331: illegal reference to string?

In this post, you’ll learn more about the Oracle ErrorPLS-00331: illegal reference to string with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

PLS-00331: illegal reference to string

Reason for the Error PLS-00331: illegal reference to string

You had an EITHER

1. an illegal reference to some object in user SYS. to use one of them in an illegal way OR

2. an illegal reference to a remote object type.

How to fix the Error PLS-00331: illegal reference to string ?

You can fix this error in Oracle by following the below steps

Remove the reference.