When Excel opens, the COM Add-in portion of adxloader64.MarketXLS.dll for Market XLS is not auto-loading. This must be done manually. And takes some time for the Add-in to load (1 minute or so). The Excel Add-in portion of the dll appears to load automatically. Excel screen goes blank sporadically while MarketXLS is active. Is MarketXLS using the GPU engine processing functionality in Excel? There is zero data transfer from/to the MarketXLS server at this time. Was working sporadically this morning However with a number of NA returns for stocks symbols that have worked fine before.