During role management, the updatepanel and login page settings are as follows:
Formsauthentication. setauthcookie (user. username, this. rememberme. Checked );
The following error occurs:
[Httpexception]: The server cannot modify the cookie after sending the HTTP header.
In system. Web. httpcookiecollection. Add (httpcookie cookie)
In system. Web. Security. rolemanagermodule. onleave (Object source, eventargs)
In system. Web. httpapplication. synceventexecutionstep. system. Web. httpapplication. iexecutionstep. Execute ()
In system. Web. httpapplication. executestep (iexecutionstep step, Boolean & completedsynchronously)
In web. config, set the attribute value of cacherolesincookie to false.
In the official forum: http://forums.asp.net/p/1069056/1574188.aspx#1574188
There are explanations.