http://www.intersoftsolutions.com/Community/WebGrid/Please-help-to-solve-this-WebGrid-isue-Validation-of-viewstate-MAC-failed-Thanks/http://www.intersoftsolutions.comenCopyright 2002 - 2015 Intersoft Solutions Corp. All rights reserved.60http://www.intersoftsolutions.com/Community/WebGrid/Please-help-to-solve-this-WebGrid-isue-Validation-of-viewstate-MAC-failed-Thanks/Thu, 18 Nov 2010 09:46:40 GMThandy@intersoftpt.com<p>Hello,</p> <p>Please let me know the step by step to replicate your issue. I think some of your project/application settings might be caused this issue.<br />Please refer into below links for more information. Hope it helps.</p> <p><a href="http://social.msdn.microsoft.com/Forums/en/vstswebtest/thread/0f143e24-65e7-4f44-8d64-a8f920f410af">http://social.msdn.microsoft.com/Forums/en/vstswebtest/thread/0f143e24-65e7-4f44-8d64-a8f920f410af</a></p> <p><a href="http://forums.asp.net/t/1166634.aspx">http://forums.asp.net/t/1166634.aspx</a></p> <p><a href="http://blogs.msdn.com/b/tom/archive/2008/03/14/validation-of-viewstate-mac-failed-error.aspx">http://blogs.msdn.com/b/tom/archive/2008/03/14/validation-of-viewstate-mac-failed-error.aspx</a></p> <p>Regards,<br />Handy</p>http://www.intersoftsolutions.com/Community/WebGrid/Please-help-to-solve-this-WebGrid-isue-Validation-of-viewstate-MAC-failed-Thanks/Thu, 18 Nov 2010 04:23:44 GMTpatrick_yuan<p>Hi,</p> <p>I got a problem while browsing WebGrid .NET page, please help to solve it. Thanks.</p> <p>Detail please see  below message:</p> <p><span> <h1>Server Error in '/cisweb/wipship' Application. <hr style="font-size: 9px; color: #c0c0c0" width="100%" /></h1> <h2><i>Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that &lt;machineKey&gt; configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.</i> </h2></span></p> <h1>Server Error in '/cisweb/wipship' Application. <hr style="font-size: 9px; color: #c0c0c0" width="100%" /></h1> <h2><i>Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that &lt;machineKey&gt; configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.</i> </h2>