---
title: Breaking changes for Optimizely Search & Navigation 12
slug: cms-12/docs/breaking-changes-for-find-12
docTags: 
createdAt: 2026-08-10T15:56:01.000Z
---

## List of changes

- `EPiServer.Find.TypeSearchExtensions.NestedConventions`
  Removed public static members from `EPiServer.Find.TypeSearchExtensions.NestedConventions`. They leaked settings between instances of
  - `EPiServer.Find.IClient`
  - `EPiServer.Find.ClientConventions.NestedConventions.MarkAsNested`
  - `EPiServer.Find.ClientConventions.NestedConventions.Contains(..)`
  - `EPiServer.Find.Helpers.Linq.ExpressionExtensions.GetNestedFieldPath(..)`
    Replace these obsolete references with `client.Conventions.NestedConventions.Contains(..)` or `client.Conventions.FieldNameConventions.GetNestedFieldPath(..`).
- `NestedFacetExtensions`
  Moved `NestedFacetExtensions` from `EPiServer.Find.Api.Facets.NestedFacetExtensions` to `EPiServer.Find.NestedFacetExtensions`. The class is not part of the core API. It was moved to the namespace of other client extensions. So, you no longer need to add a `using` statement when inserting it.
- `EPiServer.Find.ClientConventions.NestedConventionItemWrapper`
  Separated `EPiServer.Find.ClientConventions.NestedConventionItemWrapper` into `EPiServer.Find.ClientConventions.NestedConventionItemInstanceWrapper` and `EPiServer.Find.ClientConventions.NestedConventionItemTypeWrapper`. This was done to handle differences between using `ForType(..)` and `ForInstancesOf(..)` conventions correctly.
- `EPiServer.Find.NestedFacetExtensions`
  Moved nested facet extensions into `EPiServer.Find.NestedFacetExtensions`. This change applies to:

```c#
EPiServer.Find.TypeSearchExtensions.TermsFacetFor(..)  
EPiServer.Find.TypeSearchExtensions.DateHistogramFacetFor(..)
```