# GrainReferenceNotBoundException

Package: [Microsoft.Orleans.Core.Abstractions](/orleans/docs/api/csharp/microsoft.orleans.core.abstractions/) 10.0.0

[NuGet package](https://www.nuget.org/packages/Microsoft.Orleans.Core.Abstractions) | [Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Core.Abstractions/Runtime/GrainReferenceNotBoundException.cs#L10)

```csharp
[Orleans.GenerateSerializer]
public sealed class GrainReferenceNotBoundException : OrleansException
```

Indicates that a [GrainReference](/orleans/docs/api/csharp/microsoft.orleans.core.abstractions/orleans.runtime.grainreference/) was not bound to the runtime before being used.