配置IIS出现莫名的错误

Authentication of viewstate failed. 1) If this is a cluster, edit <machineKey> configuration so all servers use the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster. 2) Viewstate can only be posted back to the same page. 3) The viewstate for this page might be corrupted.

 

这提示真的好奇怪，现在还找不到原因！求高手