& in my input xml

My xml is not going through when I have & in my input xml.
I am receiving: → Malformed entity reference: &
I know I have to replace this with & Is there any utitlity which I can use after converting my documentToXmlString on
the string data before I send it out to external system?

for documentToXMLString service select true at encode field.

Hello my partners:

I hope that you’re fine, I have the same problem with the enconding in the service xmlNodeToDocument, the error is the following:

[ISC.0042.9332] Malformed entity reference: &MS 89 GR BOLSA</MA_DES_LAR>

Could you help me with this mistake please ?

did you try pub.string.HTMLEncode?