We use FormAuthentication to manage logins and I have a case where a customer complains where he can login from one computer but to from another.
I can see in my logs that his authentican is successfull but he gets bumped back to the login page. I can reproduce the symptons by disabling cookies so I asked the customer to test if cookies are enabled on http://www.tempesttech.com/cookies/cookietest1.asp, but this came out positive.
What have I missed? Is there any antivirus/security software that can mess up (ASP.NET) cookies?
The user is using IE7 and claims to have F-secure installed.
First ask from your customer to try to login using some other browser like google chrome.
If with other browser works, then ask from your customer to clear the cookies on his browser, if he can clear only your page cookies, then you must be check if you using too much cookies, or too big ones, and create a diferent shecma.
You maybe have set to store/cache the roles on cookie – this make cookie too big ones, and big cookies create problems.