Newtonsoft Json Error converting value {null} to type 'System.Int32'
Make your tabID nullable:
public int? tabID;
Value null
could not be deserialized to integer.
That's your 6-th part of json (or 5-th starting with 0):
{\"bmk\":\"test-m\",\"state\":\"on\",\"type\":\"motor\",\"tabID\":null}
You could see, that tabID is null there.
Depending on your use case, you may also want to consider having the JSON Serializer ignore nulls
Example:
Movie movie = new Movie();
movie.Name = "Bad Boys III";
movie.Description = "It's no Bad Boys";
string included = JsonConvert.SerializeObject(movie,
Formatting.Indented,
new JsonSerializerSettings { });
// {
// "Name": "Bad Boys III",
// "Description": "It's no Bad Boys",
// "Classification": null,
// "Studio": null,
// "ReleaseDate": null,
// "ReleaseCountries": null
// }
string ignored = JsonConvert.SerializeObject(movie,
Formatting.Indented,
new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore });
// {
// "Name": "Bad Boys III",
// "Description": "It's no Bad Boys"
// }