# System.Text.Json.JsonException: A possible object cycle was detected. This can either be due to a cycle or if the object depth is larger than the maximum allowed depth of 64.

- **ID:** `dotnet/aspnetcore-json-cycle`
- **Domain:** dotnet
- **Category:** serialization_error
- **Verification:** ai_generated
- **Fix Rate:** 90%

## Root Cause

JsonSerializer encounters a circular reference in the object graph (e.g., navigation properties referencing each other) or the nesting depth exceeds the default limit.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| dotnet 6.0 | active | — | — |
| dotnet 8.0 | active | — | — |
| System.Text.Json 6.0 | active | — | — |
| System.Text.Json 8.0 | active | — | — |

## Workarounds

1. **Configure System.Text.Json to handle reference loops using ReferenceHandler.Preserve. Example in Program.cs.** (90% success)
   ```
   Configure System.Text.Json to handle reference loops using ReferenceHandler.Preserve. Example in Program.cs.
   ```
2. **Use DTOs or view models that flatten the object graph, avoiding circular references.** (85% success)
   ```
   Use DTOs or view models that flatten the object graph, avoiding circular references.
   ```
3. **Set ReferenceHandler.IgnoreCycles to ignore navigation properties that cause cycles.** (80% success)
   ```
   Set ReferenceHandler.IgnoreCycles to ignore navigation properties that cause cycles.
   ```

## Dead Ends

- **** — Does not break the cycle; serializer will still fail with stack overflow or infinite loop. (90% fail)
- **** — May hide needed data; can break client-side functionality if important relationships are omitted. (70% fail)
- **** — Newtonsoft.Json also has a default reference loop handling that throws; needs explicit configuration. (80% fail)