The aps.net app is running IIS 7.5 on win 2008 r2, the user gets this error:
Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that <machineKey> configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.
now it's not a web farm, the idle time out is set to 0, so it will never idle timeout. this happened is when the session is timeout and the user trigger a postback. the time out is 45 minutes but the user trigger the postback within the timeout period. what
may possibly cause this error?
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