For a while now, our Support team has been receiving reports from users who have been logged out of their accounts and are unable to log back in. While our coders have been unable to determine the exact cause of this issue, Support has found a workaround that should allow you to log in.
If you have been redirected to the Forced Logout page -- also known as the Lost Cookie page -- and are unable to log in using the Log In option at the top of the page, please go directly to the Log In page at archiveofourown.org/login. From there, you should be able to access your account.
We're very sorry if you've run into this issue! We have added this information to our Known Issues page and will be adding it to the Forced Logout page while our coders continue to look for a fix.