Failed to load viewstate. Happening only occasiona

Question

Details of Error are given below. This error happens only occasionally / rarely / sometimes and there aren't any steps to reproduce it.

How can I know which Control is throwing this Viewstate error?

Error Message: Failed to load viewstate. The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request. For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request.

When: Rarely / Occasionally

Steps to Recreate: Can't

Stack Trace:

System.Web.HttpUnhandledException: Exception of type 'System.Web.HttpUnhandledException' was thrown. ---> System.Web.HttpException: Failed to load viewstate.  The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request.  For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request.
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState)
   at System.Web.UI.Control.LoadViewStateRecursive(Object savedState)
   at System.Web.UI.Page.LoadAllState()
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   --- End of inner exception stack trace ---
   at System.Web.UI.Page.HandleError(Exception e)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   at System.Web.UI.Page.ProcessRequest()
   at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context)
   at System.Web.UI.Page.ProcessRequest(HttpContext context)
   at ASP.sessions_aspx.ProcessRequest(HttpContext context) in c:\windows\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\73694782\85423fe4\App_Web_mnrmfsfa.8.cs:line 0
   at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

Answer 1

I've experienced this error, it happens when there is a cross page postback.

For example: You load View A. View A loads fine, for whatever reason the conditions under which View A loaded, no longer exist. The fallback page is View B. So the user completes the form on View A and postsback. Since View A's conditions are no longer met, View A's form values are posted to View B.

Answer 2

This should probably do it for you.

http://yakshaver.blogspot.com/2011/03/greatest-viewstate-attribute-to-ever.html

Answer 3

I experienced the exact same problem. I had 2 listview in a Master page, associated with 2 updatedpanels.

Disabling the EnableViewState on the Listviews solved it for me!

Answer 4

There is a workaround for this error:

Set EnableViewstate property of all dynamically loading controls to false. This is not a complete solution; we are disabling controls' ViewState here to bypass this error.

This solution can cause other errors to raise their heads, so be careful when applying this fix.

Answer 5

I've seen this error when using a gridview. It would happen when user interaction caused a postback before the page was done rendering completely.

I believe it was fixed in VS2005 SP1 however.

Answer 6

Unfortunately there is no way to see which exactly is the guilty control that is not added correctly to the control hierarchy.

There is!

Disable "Just my code" in debugging settings. And catch all thrown exceptions (check 'thrown' for Common Language Runtime in the dialog opened by Ctrl-Alt-E).

After the exception occurs, go to the nearest stack frame where the Control object is available and examine its ClientID and parents.