ORA-64203: Destination buffer too small to hold CLOB data after character set conversion.

Summary:

How to solve ORA-64203: Destination buffer too small to hold CLOB data after character set conversion.

Content (please ensure you mask any confidential information):

I have this query:

if I run it for only a few EVALUATION_ID (line 46) everything is fine; if I run it for all population I have this error:

As far as I know the DBMS_LOB.SUBSTR function should convert CLOB to varchar2 so I'm struggling realizing what is going on. Can someone help?

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