Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster Asp.Net Error

Another solution for the above error is
define the machine key explicitly in the machine.config file:

I have a Web Application Which serving lot of customers ,but sometimes am getting below error Message

"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"

After a lot research i found that this error happening due to Timer event is firing in the Page level . i think this may helpful to those who are unable to resolve the above error