True, it does work today.
But the reason for the error still stands. Paypal sent a badly formed message in its response, and dashCommerce doesn't handle it gracefully.
I did some debugging, and in PayPalService.cs, line 292
StreamReader responseStream = new StreamReader(webRequest.GetResponse().GetResponseStream());
This method is gronking when the response stream is badly formed. Perhaps should be wrapped in a try block or something. The problem is that since it is uncaught, the exception goes up the call stack, until it is logged. Because the actual page loading code is bypassed, the user is displayed with a blank screen.
In order to provide the user with a less confusing (aka not blank) response from our dashCommerce website, we should catch the exception and at least tell the user something helpful... like providing a link to the homepage ;)