I set up a Browsium rule recently to render a SharePoint 2010 site in IE8 Standards mode.
Without the Browsium rule in place the site loaded fine but one of the Web Parts didn’t work. However when the Browsium rule was enabled, the Web Part worked fine but the user was prompted for authentication when the site initially loaded! It was as if Browsium wasn’t passing the Windows authenticated credentials during the request.
To resolve the authentication issue we can specify an ION profile flag under Advanced Profile Set which details what credentials are sent to the upstream server when automatically replying to an authentication challenge.
I’ve been playing around with Browsium Ion recently and I was testing a HTTPS URL, trying to force the default ‘Edge’ emulation mode to run in ‘IE8’ emulation mode instead. For HTTP URLs it worked fine. However with HTTPS URLS, when a new instance of iexplore.exe launched (presumably after being intercepted and spawned by Browsium Ion) the user was prompted for proxy authentication. Even upon entering correct credentials it still didn’t authenticate. After clicking ‘cancel’ dozens of times, the authentication prompt eventually went away and we saw the page rendering successfully in IE8 Emulation mode.
Specifying a Proxy Host and Port
To resolve the authentication issue we can specifically provide a proxy host and port (one that authenticates for the user) by adding the following to Advanced Profile Set for the profile in question: