Getting this error when indexing in Episerver Find: "System.Reflection.AmbiguousMatchException: Ambiguous match found."

After spending some time trying to figure out why I get a lot of these errors when Find are indexing my site I feel I need to share the info on why it happened.

The error are can come if you for example have a override property in a base class but for me I did not have that so I could not figure out why this happened.

I managed to figure out what pages that was reporting the error and after a lot of commeting out properties I ended up with identifying the problem and that was this line of code:

public virtual string Item { get; set; }

I change the name to Object and all started to work so Item seem to be a name that Episerver are using somewhere but unlike for example PageName that will generate a warning in code, it works for everything BUT indexing in Episerver Find.....

This was when I added the property to a local block I got that error, when I reproduced it on Alloy and added it directly on the PageType I got this error instead:

For this line:

var page = contentLoader.Get<PageData>(contentLink);

I got this error:

[InvalidCastException: Specified cast is not valid.]
   EPiServer.Core.PageData.get_Status() +60
   EPiServer.DataAccess.Internal.ContentDB.AssignVersionStatus(IVersionable versionStatus, DbDataReader reader) +303
   EPiServer.DataAccess.Internal.ContentLoadDB.LoadContentInternal(ContentReference contentLink, Int32 languageBranchId, DbDataReader reader) +588
   EPiServer.DataAccess.Internal.<>c__DisplayClass2_0.<Load>b__0() +208
   EPiServer.Data.Providers.Internal.<>c__DisplayClass28_0`1.<Execute>b__0() +59
   EPiServer.Data.Providers.SqlTransientErrorsRetryPolicy.Execute(Func`1 method) +51
   EPiServer.Data.Providers.Internal.SqlDatabaseExecutor.Execute(Func`1 action) +203
   EPiServer.DataAccess.Internal.ContentLoadDB.Load(ContentReference contentLink, Int32 languageBranchID) +109
   EPiServer.Core.Internal.DefaultContentProviderDatabase.Load(ContentReference contentLink, Int32 languageBranchID) +31
   EPiServer.Core.Internal.DefaultContentProvider.LoadContent(ContentReference contentLink, ILanguageSelector languageSelector) +88
   EPiServer.Core.<>c__DisplayClass115_0.<LoadContentFromCacheOrRepository>b__0() +85
   EPiServer.Framework.Cache.ObjectInstanceCacheExtensions.ReadThroughWithWait(IObjectInstanceCache cache, String cacheKey, Func`1 readValue, Func`2 evictionPolicy) +710
   EPiServer.Framework.Cache.ObjectInstanceCacheExtensions.ReadThrough(IObjectInstanceCache cache, String key, Func`1 readValue, Func`2 evictionPolicy, ReadStrategy readStrategy) +87
   EPiServer.Core.ContentProvider.LoadContentFromCacheOrRepository(ContentReference contentreference, ILanguageSelector selector) +729
   EPiServer.Core.Internal.ProviderPipelineImplementation.GetItem(ContentProvider provider, ContentReference contentLink, LoaderOptions loaderOptions) +247
   EPiServer.Core.Internal.DefaultContentLoader.TryGet(ContentReference contentLink, LoaderOptions loaderOptions, T& content) +259
   EPiServer.Core.Internal.DefaultContentLoader.Get(ContentReference contentLink, LoaderOptions loaderOptions) +73
   EPiServer.Core.Internal.DefaultContentLoader.Get(ContentReference contentLink) +68
   FindIndexBug.Helpers.UrlHelpers.PageLinkUrl(UrlHelper urlHelper, ContentReference contentLink) in C:\Temp\FindIndexBug\FindIndexBug\Helpers\UrlHelpers.cs:27
   ASP._Page_Views_Shared_Blocks_TeaserBlock_cshtml.Execute() in c:\Temp\FindIndexBug\FindIndexBug\Views\Shared\Blocks\TeaserBlock.cshtml:6
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +197
   System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +105
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +90
   System.Web.Mvc.RazorView.RenderView(ViewContext viewContext, TextWriter writer, Object instance) +256
   System.Web.Mvc.BuildManagerCompiledView.Render(ViewContext viewContext, TextWriter writer) +107
   EPiServer.Web.Mvc.ViewExtensions.Render(IView view, ViewEngineResult viewEngineResult, ViewContext context, TextWriter writer, T data) +454
   EPiServer.Web.Mvc.Internal.DefaultMvcContentRenderer.HandleRenderTemplateWithViewEngine(HtmlHelper helper, IContentData contentData, TemplateModel templateModel) +392
   EPiServer.Web.Mvc.Internal.DefaultMvcContentRenderer.Render(HtmlHelper helper, PartialRequest partialRequestHandler, IContentData contentData, TemplateModel templateModel) +88
   EPiServer.Web.Mvc.MvcContentRenderer.Render(HtmlHelper helper, PartialRequest partialRequestHandler, IContentData contentData, TemplateModel templateModel) +39
   FindIndexBug.Business.Rendering.ErrorHandlingContentRenderer.Render(HtmlHelper helper, PartialRequest partialRequestHandler, IContentData contentData, TemplateModel templateModel) in C:\Temp\FindIndexBug\FindIndexBug\Business\Rendering\ErrorHandlingContentRenderer.cs:37
   EPiServer.Web.Mvc.Html.IContentDataExtensions.RenderContentData(HtmlHelper html, IContentData contentData, Boolean isContentInContentArea, TemplateModel templateModel, IContentRenderer contentRenderer) +469
   EPiServer.Web.Mvc.Html.ContentAreaRenderer.RenderContentAreaItem(HtmlHelper htmlHelper, ContentAreaItem contentAreaItem, String templateTag, String htmlTag, String cssClass) +934
   EPiServer.Web.Mvc.Html.ContentAreaRenderer.RenderContentAreaItems(HtmlHelper htmlHelper, IEnumerable`1 contentAreaItems) +119
   EPiServer.Web.Mvc.Html.ContentAreaRenderer.Render(HtmlHelper htmlHelper, ContentArea contentArea) +265
   EPiServer.Web.Mvc.Html.ContentAreaExtensions.RenderContentArea(HtmlHelper htmlHelper, ContentArea contentArea) +50
   ASP.util_views_shared_displaytemplates_contentarea_ascx.__Render__control1(HtmlTextWriter __w, Control parameterContainer) in C:\Temp\FindIndexBug\FindIndexBug\Util\Views\Shared\DisplayTemplates\ContentArea.ascx:4
   System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +103
   System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +9
   System.Web.UI.Control.Render(HtmlTextWriter writer) +10
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +129
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +287
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +27
   System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +197
   System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +9
   System.Web.Mvc.ViewPage.Render(HtmlTextWriter writer) +53
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +129
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +287
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +27
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5640

I changed it and instead added the property into a local block (that I had in the real solution) and then the site loaded but I get the Ambiguous match when indexing.

So, do not create properties with the name Item if you like to use Episerver!