Unexpected character encountered while parsing value

Question

Currently, I have some issues. I'm using C# with Json.NET. The issue is that I always get:

{"Unexpected character encountered while parsing value: e. Path '', line 0, position 0."}

So the way I'm using Json.NET is the following. I have a Class which should be saved. The class looks like this:

public class stats
{
    public string time { get; set; }
    public string value { get; set; }
}

public class ViewerStatsFormat
{
    public List<stats> viewerstats { get; set; }
    public String version { get; set; }

    public ViewerStatsFormat(bool chk)
    {
        this.viewerstats = new List<stats>();
    }
}

One object of this class will be filled and saved with:

 File.WriteAllText(tmpfile, JsonConvert.SerializeObject(current), Encoding.UTF8);

The saving part works fine and the file exists and is filled. After that the file will be read back into the class with:

try 
{ 
    ViewerStatsFormat current = JsonConvert.DeserializeObject<ViewerStatsFormat>(tmpfile);
    //otherstuff        
}
catch(Exception ex)
{
    //error loging stuff
}

Now on the current= line comes the exception:

{"Unexpected character encountered while parsing value: e. Path '', line 0, position 0."}

I don't know why this comes. The JSON file is the following -> Click me I am the JSON link

Does anyone have any ideas?

Do you always face this issue no matter what the data? Once when I faced such an issue, the reason was that the service was sending invalid UTF-8 characters. — ankhuri, Apr 24 '14 at 03:54
assuming that is not a problem, what else? recv Exception-> {"topic":"robot1/Log","Msg":"Pilot Running"} Unexpected character encountered while parsing value: o. Path '', line 0, position 0. — Spiked3, Mar 26 '15 at 17:48
I found the answer to above. https://stackoverflow.com/a/55951414/495157 — JGFMK, May 02 '19 at 11:26
I was just pulling my hair out why I was running into the same issue.... yeah, forgot to read the file and that JsonConvert.DeserializeObject<> doesn't read the file for you. Thanks. — JSWulf, Mar 30 '23 at 22:44

score 201 · Accepted Answer · edited Nov 13 '18 at 23:43

201

Possibly you are not passing JSON to DeserializeObject.

It looks like from File.WriteAllText(tmpfile,... that type of tmpfile is string that contain path to a file. JsonConvert.DeserializeObject takes JSON value, not file path - so it fails trying to convert something like @"c:\temp\fooo" - which is clearly not JSON.

edited Nov 13 '18 at 23:43

MrBoJangles

12,127
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answered Apr 24 '14 at 03:23

Alexei Levenkov

98,904
14
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179

I was using JsonConvert.DeserializeObject to deserialize response which is string and not json. Hence it was throwing the above error. – Bijay Nandagiri Sep 14 '20 at 07:29

Eduardo Pelais · Answer 2 · 2020-04-29T14:28:36.357

97

I solved the problem with these online tools:

To check if the Json structure is OKAY: http://jsonlint.com/
To generate my Object class from my Json structure: https://www.jsonutils.com/

The simple code:

RootObject rootObj= JsonConvert.DeserializeObject<RootObject>(File.ReadAllText(pathFile));

edited Apr 29 '20 at 14:28

answered Mar 04 '16 at 21:02

Eduardo Pelais

1,627
15
21

5

***How-to*** `check if the Json structure` is OKAY in C# ? – Kiquenet Apr 20 '18 at 08:06
2

Perhaps the aswers here could help you: https://stackoverflow.com/questions/14977848/how-to-make-sure-that-string-is-valid-json-using-json-net – Eduardo Pelais Apr 20 '18 at 12:52

score 26 · Answer 3 · answered Dec 29 '19 at 19:19

26

In my case, the file containing JSON string had BOM. Once I removed BOM the problem was solved.

answered Dec 29 '19 at 19:19

Aleksei Mialkin

2,257
1
28
26

I had a similar problem—but VS2019 parsing the launchSettings.json file—and had to change it from UTF-8-BOM to UTF-8. – Nathan Goings Oct 07 '20 at 14:25
2

If you are lucky enough to be the person who is writing the JSON, you can prevent the BOM from being written like so: "using (var streamWriter = new StreamWriter(someStream, new UTF8Encoding(false))) ..." – Kevin D. Apr 15 '21 at 04:51
This was the case in my issue as well. And there was one more issue after this. The JSON parsed was not matching with my BaseObject. – Deepak paramesh Nov 04 '22 at 14:34

Brandon Minnick · Answer 4 · 2017-10-27T00:41:52.673

I experienced the same error in my Xamarin.Android solution.

I verified that my JSON was correct, and noticed that the error only appeared when I ran the app as a Release build.

It turned out that the Linker was removing a library from Newtonsoft.JSON, causing the JSON to be parsed incorrectly.

I fixed the error by adding Newtonsoft.Json to the Ignore assemblies setting in the Android Build Configuration (screen shot below)

JSON Parsing Code

static readonly JsonSerializer _serializer = new JsonSerializer();
static readonly HttpClient _client = new HttpClient();

static async Task<T> GetDataObjectFromAPI<T>(string apiUrl)
{
    using (var stream = await _client.GetStreamAsync(apiUrl).ConfigureAwait(false))
    using (var reader = new StreamReader(stream))
    using (var json = new JsonTextReader(reader))
    {
        if (json == null)
            return default(T);

        return _serializer.Deserialize<T>(json);
    }
}

Visual Studio Mac Screenshot

Visual Studio Screenshot

score 18 · Answer 5 · answered Nov 23 '19 at 09:51

18

I have also encountered this error for a Web API (.Net Core 3.0) action that was binding to a string instead to an object or a JObject. The JSON was correct, but the binder tried to get a string from the JSON structure and failed.

So, instead of:

[HttpPost("[action]")]
public object Search([FromBody] string data)

I had to use the more specific:

[HttpPost("[action]")]
public object Search([FromBody] JObject data)

answered Nov 23 '19 at 09:51

Alexei - check Codidact

22,016
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It was a headache for me too, but it makes sense because every json is a key-value pair and you should provide a class with properties as keys to correctly map json to an instance of that class – Eugene Zakharov Mar 28 '20 at 20:10
This deserves more than 1 upvote from me! I spend hours and considered abandonment of a particular exercise before stumbling on your tip. – Ger Feb 16 '22 at 06:39

score 8 · Answer 6 · edited Feb 01 '18 at 09:39

This issue is related to Byte Order Mark in the JSON file. JSON file is not encoded as UTF8 encoding data when saved. Using File.ReadAllText(pathFile) fix this issue.

When we are operating on Byte data and converting that to string and then passing to JsonConvert.DeserializeObject, we can use UTF32 encoding to get the string.

byte[] docBytes = File.ReadAllBytes(filePath);

string jsonString = Encoding.UTF32.GetString(docBytes);

score 6 · Answer 7 · edited Apr 17 '19 at 13:46

6

I had the same problem with webapi in ASP.NET core, in my case it was because my application needs authentication, then it assigns the annotation [AllowAnonymous] and it worked.

[AllowAnonymous]
public async Task <IList <IServic >> GetServices () {
        
}

edited Apr 17 '19 at 13:46

Joey

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answered Apr 17 '19 at 11:57

Celso Xavier Luz

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I'm late to the party on this, but this was my issue as well. When examining the "json" going into my Deserialize method, it showed it was trying to authenticate with the API. – Ben Dec 11 '19 at 15:45

pkucas · Answer 8 · 2022-08-09T19:36:39.857

In my case, I was getting an error on JsonConvert.PopulateObject(). My request was returning JSON that was wrapped in an extra pair of '[ ]' brackets, making my result an array of one object rather than just an object. Here's what I did to get inside these brackets (only for that type of model):

           T jsonResponse = new T();
           var settings = new JsonSerializerSettings
           {
               DateParseHandling = DateParseHandling.DateTimeOffset,
               NullValueHandling = NullValueHandling.Ignore,
           };
           var jRslt = response.Content.ReadAsStringAsync().Result;
           if (jsonResponse.GetType() == typeof(myProject.Models.MyModel))
           {
               var dobj = JsonConvert.DeserializeObject<MyModel[]>(jRslt);
               var y = dobj.First();
               var szObj = JsonConvert.SerializeObject(y);
               JsonConvert.PopulateObject(szObj, jsonResponse, settings);
           }
           else
           {
               JsonConvert.PopulateObject(jRslt, jsonResponse);
           }

score 3 · Answer 9 · answered Oct 26 '21 at 15:21

3

I ran into this issue and it ended up being because of BOM characters in my input string.

Here's what I ended up doing:

String.Trim(new char[] { '\uFEFF', '\u200B' });

This resolved the issue for me.

answered Oct 26 '21 at 15:21

Jayesh Modha

61
1

score 2 · Answer 10 · edited Jul 23 '20 at 08:35

2

If you are using downloading data using url...may need to use

var result = client.DownloadData(url);

edited Jul 23 '20 at 08:35

Liam

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answered Mar 23 '17 at 20:08

Taran

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25
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score 1 · Answer 11 · answered May 02 '19 at 11:31

In my scenario I had a slightly different message, where the line and position were not zero.

E. Path 'job[0].name', line 1, position 12.

This was the top Google answer for the message I quoted.

This came about because I had called a program from the Windows command line, passing JSON as a parameter.

When I reviewed the args in my program, all the double quotes got stripped. You have to reconstitute them.

I posted a solution here. Though it could probably be enhanced with a Regex.

score 1 · Answer 12 · answered Jul 22 '19 at 16:06

I had a similar error and thought I'd answer in case anyone was having something similar. I was looping over a directory of json files and deserializing them but was getting this same error.

The problem was that it was trying to grab hidden files as well. Make sure the file you're passing in is a .json file. I'm guessing it'll handle text as well. Hope this helps.

score 1 · Answer 13 · answered Apr 06 '22 at 20:26

I had simular problem. In my case the problem was in DateTime format. It was just numbers and it is also know as EpochFormat or UnixTimestamp. A part from my JSON:

"direction": "outbound",
"date_archive": 1554691800224,
"date_doc": 1524700800000,
"date_sent": 1524704189000,
"date_received": 1524704189000,
"date_store_till": 1712544600224,

So I've used an attribute like this:

[JsonProperty("date_received")]
[JsonConverter(typeof(MicrosecondEpochConverter))]
public DateTime? DateReceived { get; set; }

You can find MicrosecondEpochConverter code here: https://stackoverflow.com/a/19972214/4324624

score 1 · Answer 14 · answered May 01 '23 at 11:33

1

Note that maybe your JSON contain extra " " in the values.

answered May 01 '23 at 11:33

Majid

13,853
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A. Almazidi · Answer 15 · 2018-09-07T06:49:52.143

0

I faced similar error message in Xamarin forms when sending request to webApi to get a Token,

Make sure all keys (key : value) (ex.'username', 'password', 'grant_type') in the Json file are exactly what the webApi expecting, otherwise it fires this exception.

Unhandled Exception: Newtonsoft.Json.JsonReaderException: Unexpected character encountered while parsing value: <. Path '', line 0, position 0

edited Sep 07 '18 at 06:49

answered Sep 07 '18 at 06:42

A. Almazidi

25
1
5

score 0 · Answer 16 · answered Feb 01 '19 at 02:56

Please check the model you shared between client and server is same. sometimes you get this error when you not updated the Api version and it returns a updated model, but you still have an old one. Sometimes you get what you serialize/deserialize is not a valid JSON.

score 0 · Answer 17 · answered Jan 14 '22 at 23:17

0

In my case, it was the lack of a default parameterless constructor !!!

answered Jan 14 '22 at 23:17

A.B.

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score 0 · Answer 18 · answered Mar 01 '22 at 00:53

0

In my case, I was calling the async service method without using await, so before Task is completed I was trying to return the result!

answered Mar 01 '22 at 00:53

EspressoCode

287
3
8

score -1 · Answer 19 · edited Nov 07 '20 at 13:59

-1

This error occurs when we parse json content to model object. Json content type is string. For example: https://dotnetfiddle.net/uFClKj Some times, an api that we call may return an error. If we do not check the response status, but proceed to parse the response to model, this issue will occur.

edited Nov 07 '20 at 13:59

shr

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answered Nov 07 '20 at 09:13

Diem Nguyen

39
4

score -2 · Answer 20 · answered May 11 '16 at 07:35

-2

Suppose this is your json

{
  "date":"11/05/2016",
  "venue": "{\"ID\":12,\"CITY\":Delhi}"
}

if you again want deserialize venue, modify json as below

{
  "date":"11/05/2016",
  "venue": "{\"ID\":\"12\",\"CITY\":\"Delhi\"}"
}

then try to deserialize to respective class by taking the value of venue

answered May 11 '16 at 07:35

Hrishikesh T T

339
2
11

1

Hi, I am using JsonConvert.SerializeObject, which will produce the first result form me, how do I get the second one ? – user123456 Sep 27 '16 at 06:31
This does not answer the question that was asked. – Brian Rogers Oct 24 '19 at 18:20

score -2 · Answer 21 · edited Sep 27 '16 at 13:28

-2

When I encountered a similar problem, I fixed it by substituting &mode=xml for &mode=json in the request.

edited Sep 27 '16 at 13:28

ryanyuyu

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answered Sep 26 '16 at 12:42

AlfredBauer

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Unexpected character encountered while parsing value

21 Answers21

JSON Parsing Code

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