I am getting the follwing error,please tell me why this error is coming
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.
Best Answer
this can happen when you post a form which in the meantime has been updated on the server, or the app has been recycled in IIS.