Internet Explorer 9 Authentication Issue — strange characters in URL

Question

I have a asp.net 2.0 C# 3.5 site that has been working like a champ. But now with Internet Explorer 9, something is very very wrong.

After authenticating (Forms with Membership Provider) the user is left on the default page but the URL is very wrong. They are authenticated.

When login is complete they should be landing here: http://20h1vg1/portal/page/Default.aspx

Instead they are getting here: http://20h1vg1/(F(u46-heLElGwm0nrfgWlskg-8oWtK9FPfEOj4Q1Qldxs16-QxzT6Y540g-kzmejxi-Emd2qfnQI1DdGq4Of-pubTA1-b_v-9UPRh7cxeVC801))/portal/page/Default.aspx

Clicking on any link after login kicks the user back out to the login screen because the aren't authenticated to the normal site path.

The characters seems session specific but I don't see any correlation to the session and the redirect after the authentication is not the issue.

Where is that string coming from. I don't see a way to see the current URL for the site that has that string in it.

Answer 1

It seems that Internet Explorer 9's default for cookless is to run without cookies. And that is what was in the URL.

If you site already requires cookies, changing the Form's authentication in the web.config to cookieless="UseCookies" fixes the problem.