I write this code:
public void ProcessRequest(HttpContext context)
{
    string m_order;
    try
    {
        var jsonSerilizer = new JavaScriptSerializer();
        var jsonString = String.Empty;
        context.Request.InputStream.Position = 0;
        using (var inputStream = new StreamReader(context.Request.InputStream))
        {
            jsonString = inputStream.ReadToEnd();
        }
        List<myClass> tmp = JsonConvert.DeserializeObject<List<myClass>>(jsonString);
        for (int i = 0; i < tmp.Count(); i++)
        {
            File.AppendAllText(@"d:\status\LOL.txt", "tmp["+(i+1)+"].rid=" +tmp[i].r_id  + "\r\n", Encoding.UTF8);
        }
myClass is defined as:
public class myClass
{
    public int f_id{get; set; }
    public int r_id { get; set; }
    public int count { get; set; }
    public int c_id { get; set; }
}
When I send the JSON string from the client to my server, my server goes to the HTTP Handler and returns the following JSON string, all as expected.
[
    {
        f_id:100,
        r_id:200,
        count:2,
        c_id=111
    },
    {
        f_id:120,
        r_id:200,
        count:1,
        c_id=111
    }
]
But when program hits this line:
List<myClass> tmp = JsonConvert.DeserializeObject<List<myClass>>(jsonString);
my server crashes with the following exception.
Newtonsoft.Json.JsonReaderException: Invalid JavaScript property identifier character: =. Path '[0].count', line 2, position 32.
   at Newtonsoft.Json.JsonTextReader.ParseUnquotedProperty()
   at Newtonsoft.Json.JsonTextReader.ParseProperty()
   at Newtonsoft.Json.JsonTextReader.ParseObject()
   at Newtonsoft.Json.JsonTextReader.ReadInternal()
   at Newtonsoft.Json.JsonTextReader.Read()
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.PopulateObject(Object newObject, JsonReader reader, JsonObjectContract contract, JsonProperty member, String id)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.PopulateList(IList list, JsonReader reader, JsonArrayContract contract, JsonProperty containerProperty, String id)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateList(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, Object existingValue, String id)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)
   at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType)
   at Newtonsoft.Json.JsonConvert.DeserializeObject(String value, Type type, JsonSerializerSettings settings)
   at Newtonsoft.Json.JsonConvert.DeserializeObject[T](String value, JsonSerializerSettings settings)
   at Portal.Get_O.ProcessRequest(HttpContext context)


c_id=111where it should be printingc_id:111. It's hard to say exactly why that's happening without knowing your server code, but I get the impression you aren't using JSON.net there, so you might want to look into that.