Invalid Viewstate error
<p>i got this error. how can i solve this?</p>

<p>EVENT # 31890</p>

<p>EVENT LOG Application</p>

<p>EVENT TYPE Warning</p>

<p>OPCODE Info</p>

<p>SOURCE ASP.NET 4.0.30319.0</p>

<p>CATEGORY Web Event</p>

<p>EVENT ID 1309</p>

<p>COMPUTERNAME  WEB2</p>

<p>DATE / TIME  23.07.2010 14:10:09</p>

<p>MESSAGE</p>

<p>Event code: 3005 </p>

<p>Event message: An unhandled exception has occurred.</p>

<p>Event time: 23.07.2010 14:10:09 </p>

<p>Event time (UTC): 23.07.2010 11:10:09 </p>

<p>Event ID: 4ccc84959e7849868332f2f75fadcda9 </p>

<p>Event sequence: 8713 </p>

<p>Event occurrence: 15 </p>

<p>Event detail code: 0 </p>

<p>Application information: </p>

<p>Application domain: /LM/W3SVC/21/ROOT-3-129243421900200000 </p>

<p>Trust level: Full</p>

<p>Application Virtual Path: / </p>

<p>Application Path: E:\Core\eCom\emagaza.deneme.com.tr\ </p>

<p>Machine name: WEB2 </p>

<p>Process information: </p>

<p>Process ID: 10148 </p>

<p>Process name: w3wp.exe </p>

<p>Account name: NT AUTHORITY\NETWORK SERVICE </p>

<p>Exception information: </p>

<p>Exception type: HttpException </p>

<p>Exception message: </p>

<p>Invalid viewstate.
at System.Web.UI.Page.DecryptStringWithIV(String s, IVType ivType) at System.Web.Handlers.AssemblyResourceLoader.System.Web.IHttpHandler.ProcessRequest(HttpContext context)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean&amp; completedSynchronously)</p>

<p>Request information: </p>

<p>Request URL: <a href="http://emagaza.deneme.com.tr/WebResource.axd?d=_uDhmp2fdIuSell_URL=" rel="nofollow">http://emagaza.deneme.com.tr/WebResource.axd?d=_uDhmp2fdIuSell_URL=</a> 
Request path: /WebResource.axd </p>

<p>User: </p>

<p>Is authenticated: False 
Authentication Type: 
Thread account name: NT AUTHORITY\NETWORK SERVICE </p>

<p>Thread information: 
Thread ID: 29 
Thread account name: NT AUTHORITY\NETWORK SERVICE </p>

<p>Is impersonating: False</p>

<p>Stack trace: at System.Web.UI.Page.DecryptStringWithIV(String s, IVType ivType)
at System.Web.Handlers.AssemblyResourceLoader.System.Web.IHttpHandler.ProcessRequest(HttpContext context)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean&amp; completedSynchronously)</p>

<p>Custom event details: </p>
