When browsing to the Outlook Web Access URL of a Microsoft Exchange Server 2010 installation, the login form is displayed correctly, however attempting to login results in a HTTP 500 error with the symptoms below.
Internet Explorer shows The website cannot display this page with a cause code of HTTP 500.
Mozilla Firefox shows a blank page.
Google Chrome shows This site can't be reached with error ERR_RESPONSE_HEADERS_TRUNCATED.
This issue may be caused by the Microsoft Exchange Forms-Based Authentication service on the Client Access Server you are connecting to not being started.
Starting this service should resolve the issue.