We have an upgraded site and are getting following error in EPiServer CMS when trying to set access rights:

Could not create instance of content type "CommerceRootContentType" since it has an invalid .NET class associated: EPiServer.Business.Commerce.ContentProviders.CommerceRootContent, EPiServer.Business.Commerce, Version=7.0.229.0, Culture=neutral, PublicKeyToken=8fe83dea738b45b7

Here is the stack:

[EPiServerException: Could not create instance of content type "CommerceRootContentType" since it has an invalid .NET class associated: EPiServer.Business.Commerce.ContentProviders.CommerceRootContent, EPiServer.Business.Commerce, Version=7.0.229.0, Culture=neutral, PublicKeyToken=8fe83dea738b45b7]
   EPiServer.Construction.ContentFactory.CreateInstance(ContentType contentType) +564
   EPiServer.Construction.ContentFactory.CreateContent(ContentType contentType, BuildingContext buildingContext) +46
   EPiServer.Commerce.Catalog.Provider.Construction.CatalogContentFactory.CreateContent(ContentType contentType, BuildingContext buildingContext) +144
   EPiServer.DataAccess.ContentDB.CreateContent(ContentType contentType) +20
   EPiServer.DataAccess.ContentListDB.ReadPageList(DbCommand cmd) +699
   EPiServer.DataAccess.<>c__DisplayClass22.b__21() +598
   EPiServer.Data.Providers.<>c__DisplayClass1`1.b__0() +60
   EPiServer.Data.Providers.SqlTransientErrorsRetryPolicy.Execute(Func`1 method) +147
   EPiServer.DefaultContentProvider.LoadContents(IList`1 contentReferences, ILanguageSelector selector) +602
   EPiServer.Core.ContentProvider.GetScatteredContents(IEnumerable`1 contentLinks, ILanguageSelector selector) +458
   EPiServer.Core.ContentProvider.LoadChildren(ContentReference contentLink, ILanguageSelector selector, Int32 startIndex, Int32 maxRows) +538
   EPiServer.DataFactory.GetChildren(ContentReference contentLink, ILanguageSelector selector, Int32 startIndex, Int32 maxRows) +1441
   EPiServer.DataFactory.GetChildren(ContentReference contentLink, ILanguageSelector selector) +89
   EPiServer.UI.WebControls.ContentDataSource.ContentDataSource.GetFilteredChildren(ContentReference contentLink) +251
   EPiServer.UI.WebControls.ContentDataSource.ContentHierarchyData.EnsureChildrenLoaded() +79
   EPiServer.UI.WebControls.ContentDataSource.ContentHierarchyData.GetChildren() +19
   EPiServer.UI.WebControls.PageTreeView.PopulateChildNodes(IHierarchicalEnumerable enumerable, Int32 depth, Int32 expandDepth, PageTreeNode parentNode, ArrayList populationPath) +814
   EPiServer.UI.WebControls.PageTreeView.PopulateRecursive(String viewPath) +466
   EPiServer.UI.WebControls.PageTreeView.PerformDataBinding() +170
   System.Web.UI.WebControls.HierarchicalDataBoundControl.PerformSelect() +140
   System.Web.UI.WebControls.BaseDataBoundControl.EnsureDataBound() +146
   System.Web.UI.Control.EnsureChildControls() +189
   System.Web.UI.Control.PreRenderRecursiveInternal() +60
   System.Web.UI.Control.PreRenderRecursiveInternal() +222
   System.Web.UI.Control.PreRenderRecursiveInternal() +222
   System.Web.UI.Control.PreRenderRecursiveInternal() +222
   System.Web.UI.Control.PreRenderRecursiveInternal() +222
   System.Web.UI.Control.PreRenderRecursiveInternal() +222
   System.Web.UI.Control.PreRenderRecursiveInternal() +222
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +4297

We don't have any references in the config files in the project to that version, no assemblies in the bin files for the two sites that are from the previous version, and I've cleaned temp internet files.

Any ideas?

/J