# rpc error: code = Internal desc = grpc: error while marshaling: string field contains invalid UTF-8

- **ID:** `go/grpc-invalid-header`
- **Domain:** go
- **Category:** data_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

A string field in the proto message contains invalid UTF-8 bytes, which violates proto3 string requirements.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 1.11 | active | — | — |

## Workarounds

1. **** (90% success)
   ```
   req.Name = strings.ToValidUTF8(req.Name, "")
   ```
2. **** (50% success)
   ```
   marshaler := protojson.MarshalOptions{EmitUnpopulated: true}; data, _ := marshaler.Marshal(msg)
   ```

## Dead Ends

- **** — Changing field type requires proto regeneration and may break compatibility. (60% fail)
- **** — The marshaling will fail and the RPC will not complete. (100% fail)