Failed to execute function

Failed to execute function

In a function, i want to see a custom field : "Repres" of my users
I see the field but the function has a problem next the info.

args = Map();
args.put("action","quotationHeader");
code_rep = "";
repres = zoho.crm.getRecords("users");
//info repres;
for each  rep in repres
{
for each  r in rep
{
if(r.containsKey("email"))
{
if(r.getJSON("email").equals(zoho.loginuserid))
{
code_rep = r.getJSON("Repres");
info code_rep;
}
}
}
}
return "";

I see :
Info
  • AMA
Failed to execute function
  • Function specified in criteria has returned null value and it cannot be evaluated Line Number:12
My Object are : 

{
  "users": [
    {
      "country": null,
      "role": {
        "name": "Gestionnaire de secteur",
        "id": "1234"
      },
      "city": null,
      "language": "fr_FR",
      "locale": "fr_FR",
      "microsoft": false,
      "Isonline": false,
      "Modified_By": {
        "name": "Service Info",
        "id": "1235"
      },
      "street": null,
      "Currency": "EUR",
      "alias": null,
      "id": "1234",
      "state": null,
      "fax": null,
      "country_locale": "FR",
      "first_name": "jennifer",
      "email": "kkk @kk.com",
      "Reporting_To": null,
      "zip": null,
      "created_time": "2019-09-13T15:35:00+02:00",
      "Modified_Time": "2019-09-19T11:34:53+02:00",
      "website": null,
      "time_format": "hh:mm a",
      "offset": 7200000,
      "profile": {
        "name": "Administrator",
        "id": "1234"
      },
      "mobile": null,
      "last_name": "Leclerc",
      "time_zone": "Europe/Paris",
      "created_by": {
        "name": "Service Info",
        "id": "1234"
      },
      "Extension_Number": null,
      "zuid": "20067595230",
      "confirm": true,
      "Repres": null,
      "full_name": "jennifer Leclerc",
      "territories": [
        
      ],
      "phone": null,
      "dob": null,
      "date_format": "dd/MM/yyyy",
      "status": "active"
    },
....