Question

Running the ASP.NET webforms run the application works fine. When the application is idle for 4 to 5 minutes, it is giving 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.

How can this be solved?

Answer 1

Modify your web.config with this element:

<pages validateRequest="false" 
       enableEventValidation="false" 
       viewStateEncryptionMode ="Never" />

Any more info required, refer to the ASP.NET Forums topic