An error occurred while attaching module (Dynamicweb.Frontend.Content)

System.InvalidOperationException: Collection was modified; enumeration operation may not execute.
   at System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource)
   at System.Collections.Generic.List`1.Enumerator.MoveNextRare()
   at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source, Func`2 predicate)
   at Dynamicweb.DataManagement.ViewSetting.get_Connection()
   at Dynamicweb.DataManagement.ViewSetting.get_AllQueryVariables()
   at Dynamicweb.DataManagement.ViewSetting.FillQueryVariables(Criteria criteria, Dictionary`2 dictionary)
   at Dynamicweb.DataManagement.ViewSetting.GetDataForCriteria(Criteria criteria)
   at Dynamicweb.DataManagement.ViewSetting.get_Data()
   at Dynamicweb.DataManagement.PublishingRenderer.RenderPublishing(Publishing publishing, Template template)
   at Dynamicweb.DataManagement.PublishingFrontend.RenderPublishing(String result)
   at Dynamicweb.DataManagement.PublishingFrontend.GetContent()
   at Dynamicweb.Frontend.Content.GetModuleOutput(Paragraph paragraph, PageView pageview)