Hi all,

I've just upgraded from Umbraco 7.9.3 to 7.10.0

Now, when I run the project, I get the error below. I've seen this error appear lots on the forum, and it seems to point to a duplicate alias in the doc types, but I've checked, and I don't have any.

Oddly, I only get the error on first load - when I Continue and then refresh the page, I don't get the error. I can then navigate around the site and back to the original page with no errors.

You'll see in the code below that there's a commented out line where I tried just .Url instead of GetCropUrl, but I still got the same error.

I also tried deleting the image from the back-end, and assigning a new image, but I still got the same error.

Any ideas would be appreciated.

Server Error in '/' Application.
An item with the same key has already been added.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.ArgumentException: An item with the same key has already been added.

Source Error: 


Line 25:         {
Line 26:             var image = item.GetPropertyValue<IPublishedContent>("image");
Line 27:             var responsiveImage = image.GetCropUrl("Hotspot portrait");
Line 28:             //var responsiveImage = image.Url;
Line 29:             <a href="@Umbraco.NiceUrl(item.GetPropertyValue<int>("linkURL"))" class="hotspot-item">

Source File: c:\Users\paul\source\repos\PaulMcGSite\PaulMcGSite\Views\Home.cshtml    Line: 27 

Stack Trace: 


[ArgumentException: An item with the same key has already been added.]
   System.ThrowHelper.ThrowArgumentException(ExceptionResource resource) +52
   System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add) +183
   Umbraco.Core.Services.IdkMap.Populate(IEnumerable`1 pairs, UmbracoObjectTypes umbracoObjectType) +319
   Umbraco.Web.PublishedCache.XmlPublishedCache.PublishedContentCache.EnsureIdkMap(UmbracoContext umbracoContext) +294
   Umbraco.Web.PublishedCache.XmlPublishedCache.PublishedContentCache.GetById(UmbracoContext umbracoContext, Boolean preview, Guid nodeKey) +40
   Umbraco.Web.PublishedCache.ContextualPublishedContentCache.GetById(Boolean preview, Guid contentKey) +71
   Umbraco.Web.PublishedContentQuery.TypedContent(Guid id) +158
   Umbraco.Web.PublishedContentQueryExtensions.TypedContent(ITypedPublishedContentQuery contentQuery, Udi id) +96
   Umbraco.Web.PropertyEditors.ValueConverters.ContentPickerPropertyConverter.ConvertSourceToObject(PublishedPropertyType propertyType, Object source, Boolean preview) +260
   Umbraco.Web.Models.DetachedPublishedProperty.<.ctor>b__7_1() +49
   System.Lazy`1.CreateValue() +411
   System.Lazy`1.LazyInitValue() +152
   System.Lazy`1.get_Value() +75
   Umbraco.Web.Models.DetachedPublishedProperty.get_Value() +9
   Umbraco.Web.PublishedPropertyExtension.GetValue(IPublishedProperty property, Boolean withDefaultValue, T defaultValue) +68
   Umbraco.Web.PublishedContentExtensions.GetPropertyValue(IPublishedContent content, String alias) +30
   ASP._Page_Views_Home_cshtml.Execute() in c:\Users\paul\source\repos\PaulMcGSite\PaulMcGSite\Views\Home.cshtml:27
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +198
   System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +105
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +78
   System.Web.Mvc.RazorView.RenderView(ViewContext viewContext, TextWriter writer, Object instance) +256
   System.Web.Mvc.BuildManagerCompiledView.Render(ViewContext viewContext, TextWriter writer) +107
   Umbraco.Core.Profiling.ProfilingView.Render(ViewContext viewContext, TextWriter writer) +113
   System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context) +290
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResult(ControllerContext controllerContext, ActionResult actionResult) +13
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult) +56
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult) +420
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult) +420
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult) +420
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult) +52
   System.Web.Mvc.Async.<>c__DisplayClass2b.<BeginInvokeAction>b__1c() +173
   System.Web.Mvc.Async.<>c__DisplayClass21.<BeginInvokeAction>b__1e(IAsyncResult asyncResult) +100
   System.Web.Mvc.Async.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult) +10
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +27
   System.Web.Mvc.Controller.<BeginExecuteCore>b__1d(IAsyncResult asyncResult, ExecuteCoreState innerState) +13
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +29
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +36
   System.Web.Mvc.Controller.<BeginExecute>b__15(IAsyncResult asyncResult, Controller controller) +12
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +22
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +26
   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10
   System.Web.Mvc.MvcHandler.<BeginProcessRequest>b__5(IAsyncResult asyncResult, ProcessRequestState innerState) +21
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +29
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +49
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +28
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +9748665
   System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) +48
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +159

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.7.2633.0