Hi,

I’m having an issue with Tea Commerce. Basically, it is causing (intermittent) LINQ errors:

Exception: System.InvalidOperationException: Collection was modified; enumeration operation may not execute.

   at System.Collections.Generic.List`1.Enumerator.MoveNextRare()

   at System.Linq.Enumerable.SingleOrDefault[TSource](IEnumerable`1 source, Func`2 predicate)

   at TeaCommerce.Api.Services.OrderService.Get(Int64 storeId, Guid orderId)

   at TeaCommerce.Api.Web.TeaCommerceHelper.GetCurrentOrder(Int64 storeId, Boolean autoCreate)

   at TeaCommerce.Api.Web.TeaCommerceHelper.GetPrice(Int64 storeId, String productIdentifier)

   at ASP._Page_macroScripts_catalogue_product_page_cshtml.Execute() in xxxxxxx\MacroScripts\catalogue\product-page.cshtml:line 507

   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()

   at System.Web.WebPages.WebPage.ExecutePageHierarchy()

   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)

   at umbraco.MacroEngines.RazorMacroEngine.ExecuteRazor(MacroModel macro, INode currentPage)

   at umbraco.MacroEngines.RazorMacroEngine.Execute(MacroModel macro, INode currentPage)

   at umbraco.macro.loadMacroScript(MacroModel macro)

   at umbraco.macro.renderMacro(Hashtable pageElements, Int32 pageId)

I note that an older Tea Commerce version had a fix for this issue (v1.4.1.0), though we are using v 2.2.3 on Umbraco v6.2.4.

This seems to occur randomly, and results in macro script engine errors being presented to users. I understand the nature of the error but not what could possibly be causing this collection modification?? 

Is this a bug or is there some other logical explanation for this that we can fix?

Cheers,
Andy