I walked through the Javascript code for the Splash page widget. The Splash widget is trying to get the application ID from the URL. It does this when it first tries to open. Unfortunately, the way it does this will not work for an application in an iframe. I would consider it a defect in the function that ArcGIS uses to determine the URL where the widget is located.
The Splash widget’s “onOpen” function is ultimately calling a utility function to try to extract the application ID from the url:
z.getAppIdFromUrl = function() {
var b = !0
, a = window.top.location.href;
A cross-domain site in a frame can’t access those values so the browser is denying it. The utility function isn’t catching the error and behaving gracefully, so it just hangs.
You either need to not use the Splash widget, or contact Esri support and explain the issue to them, and see if it can be repaired or if there is a suggested alternative. This getAppIdFromUrl() function should be putting a try/catch block around its attempt to read the HREF and if it fails it should be falling back to trying to get the appID from elsewhere.
