hi,

I have just deployed my site (v7.3.0) and 3-4 times a day after checking the log file umbraco is throwing the below error. This only happens on the live site, I can't reproduce it locally.

It seems to happen if a user clicks a link more than once ie. double click or more. If after the error appears you refresh the page it works again...

This seems to happen on any page. I have umbraco.tracelogged my way through my master template then eventually create the error myself and each time the error is thrown after the entire master template has been processed....

2016-04-15 11:41:12,508 [P270444/D2/T13] ERROR Umbraco.Core.UmbracoApplicationBase - An unhandled exception occurred System.ArgumentException: An item with the same key has already been added. at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource) at System.Collections.Generic.Dictionary2.Insert(TKey key, TValue value, Boolean add) at System.Collections.Generic.Dictionary2.Add(TKey key, TValue value) at uWebshop.Umbraco.Repositories.PlainEntityRepository1.GetCache(ILocalization localization) at uWebshop.Umbraco.Repositories.PlainEntityRepository1.GetAll(ILocalization localization) at uWebshop.Domain.Services.EntityService1.<>c__DisplayClass6.<GetAll>b__3(String alias) at System.Collections.Concurrent.ConcurrentDictionary2.GetOrAdd(TKey key, Func2 valueFactory) at uWebshop.Domain.Services.EntityService1.GetAll(ILocalization localization, Boolean includeDisabled) at uWebshop.Domain.Services.EntityService`1.GetById(Int32 id, ILocalization localization, Boolean includeDisabled) at uWebshop.Domain.Helpers.DomainHelper.GetCategoryById(Int32 categoryId) at uWebshop.Umbraco.Mvc.UwebshopMvcApplication.PublishedContentRequestPrepared(Object sender, EventArgs e) at Umbraco.Web.Routing.PublishedContentRequest.OnPrepared() at Umbraco.Web.Routing.PublishedContentRequestEngine.PrepareRequest() at Umbraco.Web.UmbracoModule.ProcessRequest(HttpContextBase httpContext) at Umbraco.Web.UmbracoModule._8(Object sender, EventArgs e) at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

(scratching my head)

thanks

Ian