---
title: NetworkCompatibilityToken.Compatibility.sessionProtocolVersionMismatch
framework: realitykit
role: symbol
role_heading: Case
path: realitykit/networkcompatibilitytoken/compatibility/sessionprotocolversionmismatch
---

# NetworkCompatibilityToken.Compatibility.sessionProtocolVersionMismatch

An indication that two peers running incompatible versions of RealityKit can’t sync.

## Declaration

```swift
case sessionProtocolVersionMismatch
```

## Discussion

Discussion The compatibilityWith(_:) method returns this value when two devices have different OS versions and there has been a significant change in networking protocol between those releases.

## See Also

### Compatibility indicators

- [NetworkCompatibilityToken.Compatibility.compatible](realitykit/networkcompatibilitytoken/compatibility/compatible.md)