Server Error in '/Webpart' Application ????

[bansari]

my simple page redirects to the page wich contains webparts in it.
i m getting such error.plz help me.
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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.

[bansari]

I got it's solution:It may helpful to others having same problem.

Do the following changes in your web.config file.
before change it was like this:

<pages>
 <controls>
  <add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
 <add tagPrefix="asp" namespace="System.Web.UI.WebControls" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
  </controls>
</pages>

and remove this page tag and insert following:

<pages enableViewStateMac="false"></pages>

the problem will be solved. :)