How to extract Termination Notification details which are still under approval

Summary:

I am trying to create a query to extract Termination Notifications, which are still under approval.

Following is the query that I prepared.

But it's ending into error (ORA-06502: PL/SQL: numeric or value error ORA-06512: at "SYS.XMLTYPE", line 272 ORA-06512: at line 1)

If I remove where condition from the query, it works.

Appreciate, if someone can help me to address this error or with any other workaround to get the required data

Content (required):

Query Text:

With SoaRequestData as(

Select 'FutureTermination' infoType

,XMLTYPE(txnd.DATA_CACHE).EXTRACT('//PersonId/text()').getNumberVal() personId

,XMLTYPE(txnd.DATA_CACHE).EXTRACT('//selectedPerson/text()').getStringVal() selectedPerson