Problem writing xml do disk ORA-29285

Question

I have an issue when I write larger xml files. I get ORA-29285 when i flush it to disk.
The strange thing is that the code works when I use this code:
xmlText clob := xml.extract('/*').getClobVal(); But It is very slow.
instead of this:
xmlText clob := xml.getClobVal();
Anyone know the reason why the first statement works?
The code I use when it works:
procedure writeToFile (xml xmltype, filename varchar2)
is
fHandle utl_file.File_Type;
xmlText clob := xml.extract('/*').getClobVal();
/*xmlText clob := xml.getClobVal();*/
xmlTextSize binary_integer := dbms_lob.getLength(xmlText)+1;
offset binary_integer := 1;
buffer varchar2(32767);
linesize binary_integer := 32767;
byteCount binary_integer;
directory_name constant varchar2 (80) := 'RDFEXPORT';
begin
fhandle := utl_file.fopen(directory_name, filename,'w', linesize);
while (offset < xmlTextSize) loop
if (xmlTextSize - offset > linesize) then
byteCount := linesize;
else
byteCount := xmlTextSize - offset;
end if;
dbms_lob.read(xmlText, byteCount, offset, buffer);
offset := offset + byteCount;
utl_file.put(fHandle, buffer);
utl_file.fflush(fHandle);
end loop;
utl_file.new_line(fHandle);
utl_file.fclose(fHandle);
dbms_lob.FREETEMPORARY(xmlText);
end writeToFile;

Answer 1

Great thank you!
So Is there a way to add a new line when you have functions like this?
(It is rdf/xml I'm creating if someone wonders)
function medDraSoc return xmltype is
socXml xmltype;
begin
select
xmlagg
xmlelement
("isim:SOC",
xmlattributes ('#SOC' || soc.soc_code as "rdf:about"),
xmlforest
soc.soc_code as "isim:termCode",
soc.soc_costart_sym as "isim:costart",
soc.soc_harts_code as "isim:hartsCode",
soc.soc_icd10_code as "isim:icd10Code",
soc.soc_icd9_code as "isim:icd9Code",
soc.soc_icd9cm_code as "isim:icd9cmCode",
soc.soc_jart_code as "isim:jartCode",
soc.soc_name as "protons:mainLabel",
soc.soc_whoart_code as "isim:whoartCode")
) xml
into socXml
from exp_meddra_soc soc;
return socXml;
end medDraSoc;