Self referencing loop detected with type 'Forms.Data.Model'.

"Self-referencing loop detected," occurs when a JSON serializer encounters a loop in object references that it cannot resolve, leading to an infinite loop during serialization or deserialization

The error you're encountering, "Self-referencing loop detected," occurs when a JSON serializer encounters a loop in object references that it cannot resolve, leading to an infinite loop during serialization or deserialization. This issue is common when objects reference each other in a circular manner.

Solution

Step 1: Configure JsonSerializerSettings to Handle Reference Loops You can configure the JsonSerializerSettings to handle self-referencing loops by ignoring them. This is achieved with the ReferenceLoopHandling setting:

TempData["FormAndQuestionsById"] = JsonConvert.SerializeObject(data, Formatting.Indented, 
    new JsonSerializerSettings
    {
        ReferenceLoopHandling = ReferenceLoopHandling.Ignore
    });

Step 2: Retrieving and Deserializing Data from TempData

var json = TempData["FormAndQuestionsById"] as string;
if (json != null)
{
    // Deserialize JSON to the original data type
    var formData = JsonConvert.DeserializeObject<FormDto>(json, new JsonSerializerSettings
    {
        ReferenceLoopHandling = ReferenceLoopHandling.Ignore
    });
}