ASP.NET Membership user login error cookie problems

We recently updated a site from Classic ASP to ASP.Net 3.5.

The old site used a login system based on cookies. It would remember the users login information if a checkbox was selected when they first logged in. This would of course be done in a cookie.

We then upgraded the site Using ASP.net. We transferred the old users to the built in ASP.net Membe开发者_运维百科rship Authentication.

It works great except for a really strange occurrence. When a user logs in to the site, but had the old cookie for the site which stored the login information, the ASP.net Authentication seems to crash.

There is no error message, no information of any kind.

The user tries to login, gets no error message, just gets transfered back to the login page.

It seems to be looking at the old cookie and just doesn't know what to do.

The domain names of the old site and the new site are the same.

This does not occur for new users who have never been to the old site.

If an old site user clears out his cookies in his browser he can log in fine and the error never happens again.

But we have 5000 users, we can't tell all of them to clear out their cookies.

I tried changing the setting in the following line of code in my web.config.

<authentication mode="Forms">
  <forms cookieless="UseCookies" loginUrl="~\User\Login.aspx" defaultUrl="~\Default.aspx" timeout="26280000"  />
</authentication>

But I'm not sure if it helped or not.

Any assistance would be greatly appreciated.

Thanks

With forms authentication, your login is controlled by forms authentication cookie. So I don't understand how is your old cookie interfering with FAC?

In case you are storing some value in your custom cookie, one way would be change the name of the cookie in your new code. i.e. if the code is creating "CookieA", the same name as old application, change it to "CookieB" and same while reading.

Specify cookies token name:

<forms name=".ASPXFORMSAUTH" ... />