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System.Exception: Exception while creating a value. ---> System.NullReferenceException: Object reference not set to an instance of an object.
   at Marsman.UmbracoCodeFirst.Core.CodeFirstModelContext.MoveNextContext(Object instance, CodeFirstRegistration registration, CodeFirstModelContext parentContext)
   at Marsman.UmbracoCodeFirst.Converters.AutoDataTypeConverter`2.Create(Tdb input, Action`1 registerContext)
   at Marsman.UmbracoCodeFirst.Converters.DataTypeConverterBase`2.Create(Object input, Action`1 registerContext)
   at Marsman.UmbracoCodeFirst.Core.Modules.ContentModelModuleBase`3.SetPropertyValueOnModel(Object objectInstance, PropertyRegistration registration, Object umbracoStoredValue)
   at Marsman.UmbracoCodeFirst.Core.Modules.ContentModelModuleBase`3.CopyPropertyValueToModel(IPublishedContent content, Object objectInstance, PropertyRegistration registration)
   at Marsman.UmbracoCodeFirst.Core.Modules.ContentModelModuleBase`3.CreateInstanceFromPublishedContent(IPublishedContent content, ContentTypeRegistration registration, CodeFirstModelContext parentContext)
   at Marsman.UmbracoCodeFirst.Core.Modules.ContentModelModuleBase`3.ConvertToModelInternal[Tmodel](IPublishedContent content, CodeFirstModelContext parentContext)
   at ASP._Page_Views_Partials_Promos__PromoContentBlock2_cshtml.Execute() in C:\home\site\wwwroot\Views\Partials\Promos\_PromoContentBlock2.cshtml:line 9
   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()
   at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()
   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)
   at Umbraco.Core.Profiling.ProfilingView.Render(ViewContext viewContext, TextWriter writer)
   at System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData)
   at Umbraco.Core.Cache.CacheProviderExtensions.<>c__DisplayClass0_0`1.<GetCacheItem>b__0()
   at Umbraco.Core.Cache.DictionaryCacheProviderBase.<>c__DisplayClass10_0.<GetSafeLazy>b__0()
   --- End of inner exception stack trace ---
   at Umbraco.Core.Cache.HttpRuntimeCacheProvider.GetCacheItemInternal(String cacheKey, Func`1 getCacheItem, Nullable`1 timeout, Boolean isSliding, CacheItemPriority priority, CacheItemRemovedCallback removedCallback, Func`1 dependency)
   at Umbraco.Core.Cache.HttpRuntimeCacheProvider.GetCacheItem(String cacheKey, Func`1 getCacheItem, Nullable`1 timeout, Boolean isSliding, CacheItemPriority priority, CacheItemRemovedCallback removedCallback, String[] dependentFiles)
   at Umbraco.Core.Cache.DeepCloneRuntimeCacheProvider.GetCacheItem(String cacheKey, Func`1 getCacheItem, Nullable`1 timeout, Boolean isSliding, CacheItemPriority priority, CacheItemRemovedCallback removedCallback, String[] dependentFiles)
   at Umbraco.Web.CacheHelperExtensions.CachedPartialView(CacheHelper cacheHelper, HtmlHelper htmlHelper, String partialViewName, Object model, Int32 cachedSeconds, String cacheKey, ViewDataDictionary viewData)
   at Umbraco.Web.HtmlHelperRenderExtensions.CachedPartial(HtmlHelper htmlHelper, String partialViewName, Object model, Int32 cachedSeconds, Boolean cacheByPage, Boolean cacheByMember, ViewDataDictionary viewData, Func`3 contextualKeyBuilder)
   at RSM.Web.Extensions.HtmlHelperExtensions.CachedPartialByViewData(HtmlHelper helper, String partialViewName, Object inputModel, ViewDataDictionary viewData) in D:\a\1\s\src\RSM.Web\Extensions\HtmlHelperExtensions.cs:line 190
   at ASP._Page_views_partials_grid_editors_promoblocks_cshtml.Execute() in C:\home\site\wwwroot\views\partials\grid\editors\promoblocks.cshtml:line 85
   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()
   at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()
   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)
   at Umbraco.Core.Profiling.ProfilingView.Render(ViewContext viewContext, TextWriter writer)
   at System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData)
   at ASP._Page_Views_Partials_grid_editors_base_cshtml.Execute() in C:\home\site\wwwroot\Views\Partials\grid\editors\base.cshtml:line 20