Library/PackageCache/com.unity.ai.navigation@1.1.5/Editor/NavMeshAssetManager.cs(47,30): error CS1061: 'NavMeshSurface' does not contain a definition for 'IsPartOfPrefab' and no accessible extension method 'IsPartOfPrefab' accepting a first argument of type 'NavMeshSurface' could be found (are you missing a using directive or an assembly reference?)