ORA-31061: XDB error: special char to escaped char conversion failed

 
ORA-31061: XDB error: special char to escaped char conversion failed

while executing a procedure the following error thrown

exec BU_OFFER.GET_UTILIZATION_REPORT_DATA1('bbc_00205196','','ALL','',:rc)

ORA-31061: XDB error: special char to escaped char conversion failed.
ORA-06512: at "FMS_ADMIN.BU_OFFER", line 175
ORA-06512: at line 1

The query which is used for generating XML is 

SELECT 
A.ADDRESS   -- this field containing special characters 
FROM UTILIZATION_REPORT_DATA A,BU_CONNECTIONS B
WHERE  B.PHONE_NO(+)=A.FTTH_PHONE_NO
AND A.OLT_IP IN(SELECT DISTINCT OLT_IP FROM OLT_STAFF_MAPPING WHERE BBC_USERNAME = 'bbc_00205196');

changed the above query using REGEXP_REPLACE  function

SELECT 
REGEXP_REPLACE(A.ADDRESS, ''[^[:print:]]'', '''')  ADDRESS
FROM UTILIZATION_REPORT_DATA A,BU_CONNECTIONS B
WHERE  B.PHONE_NO(+)=A.FTTH_PHONE_NO
AND A.OLT_IP IN(SELECT DISTINCT OLT_IP FROM OLT_STAFF_MAPPING WHERE BBC_USERNAME = 'bbc_00205196');

This solved the issue.