Replace description specific word multi line description

[Thierry Fournier]

I try to Update the descrition of parent issue,

If my description has only one line this work fine : 

---

{
"fields": {
"description": "{{issue.description.replace("SERVEUR",issue.Nom_Serveur)}}"
}
}

---

But if My description has more than one line I have : 

Error while parsing additional fields. Not valid JSON

Do you have any idea ?