I have this same error. For years it worked and now it will not connect. My issue is that citibank now have a security notice at the top of internet banking asking to install a citibank token (which I have already done) but you can't click the notice off, its permanently there until Citibank decide to take it down. I am pretty sure this is what is effecting its ability to connect to Quickbooks. There doesn't seem to be a way around it (I've contacted them). Hope this helps someone else out with the same issue, if anyone has a fix, please let me know.