IIS ASP.Net网站 - ManagedPipelineHandler错误（尝试对不存在的网络连接执行操作）

I am experiencing a strange issue. I have an ASP.Net web application that uses Forms Authentication. If I open the log-in page and there is a couple of minutes of inactivity, the log-in attempt times out or IE / FireFox display "Cannot display this page". If there is no pause or lack of activity, there is no issue and the website run as expected.I am experiencing a strange issue. I have an AS