错误描述：
Unable to make the session state request to the session state server.
Please ensure that the ASP.NET State service is started and that the client and server ports are the same.
If the server is on a remote machine, please ensure that it accepts remote requests by checking the value of
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\aspnet_state\Parameters\AllowRemoteConnection.
If the server is on the local machine, and if the before mentioned registry value does not exist or is set to 0,
then the state server connection string must use either ‘localhost‘ or ‘127.0.0.1‘ as the server name.
错误原因：
ASP.Net State Service服务未启动。
解决办法：
Administrative Tools -> Services -> make ASP.NET State Service started.
打开windows 服务,找到 
建议将Startup type设置成Automatic(Delayed Start)
原文地址：https://www.cnblogs.com/yachao1120/p/10034087.html