Validation of viewstate MAC failed.

Friday, December 2, 2011

Question : Getting this error, "Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster."

Solution :
In your web.config file, you will find this line.

Just replace this line with below line and all your problem solved.

Please send me your questions to me, if you have any..

Thanks Hope this post will help you, if yes please put comment below of this page,
Rajesh Singh,
Asp.Net Developer
Dobazaar (Dubai, UAE)