1. Numbers shouldn't be enclosed with quotes.
2. It doesn't sound like you are building the json string correctly.
3. You should post a small example of the string that you are trying to create.
Sub Create_JSON_File
Dim JSONGenerator As JSONGenerator
Dim json_str As String
Dim data As List
data.Initialize
json_str = "os_name :Ios"
data.Add(json_str)
json_str = "os_version: 6.4.64"
data.Add(json_str)
JSONGenerator.Initialize2(data)
Msgbox(JSONGenerator.ToPrettyString(2), "")
End Sub