# beforeReloadSubsystems

> Called from SubsystemManager before reloading all XR SDK Provider packaged subsystems.

## Definition

* **Type:** Event
* **Namespace:** [UnityEngine](/engine/6000.7/script-reference/unityengine.md)
* **Assembly:** UnityEngine.SubsystemsModule

```csharp
public static event Action beforeReloadSubsystems
```

### Remarks

When the Editor starts or when packages are installed or removed, the [SubsystemManager](/engine/6000.7/script-reference/unityengine/subsystemmanager.md) searches the packages and loads all XR SDK packages that it finds. Handling this event allows you to do work you might need after the subsystem manager loads and initializes new subsystem descriptors.

Additional Resources: [SubsystemManager](/engine/6000.7/script-reference/unityengine/subsystemmanager.md), [SubsystemDescriptor](/engine/6000.7/script-reference/unityengine/subsystemdescriptor.md)