How to fix ViewStateException Invalid ViewState?

Usually you don’t see Invalid ViewState exception unless you implement some kind of ASP.NET error logger in Global.asax.

Error usually states something like this:

Exception: System.Web.HttpException: The state information is invalid for this page and might be corrupted. System.Web.UI.ViewStateException: Invalid viewstate.

Those errors are usually generated by some automatic submission form engines. Comments and contact forms are mostly effected by this exception. The end user never sees those errors, so invalid viewstate errors don’t have any value for your error logger. Let’s bypass them:

if (ex is HttpException && ex.InnerException is ViewStateException)





See my error logger article for further details.

Posted on May 23, 2010 by


Posted on 7/3/2010 10:43:15 AM by Surge

thanks for the help.

Posted on 8/18/2010 06:47:07 AM by selcuk yazar


What is the _app. ?



I took this if statement from my logger code. _app is HttpContext.Current.ApplicationInstance.

Posted on 5/18/2011 05:28:02 PM by john oliveson

Server Error in '/MDCR' Application.


The state information is invalid for this page and might be corrupted.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Web.HttpException: The state information is invalid for this page and might be corrupted.

Source Error:

[No relevant source lines]

Source File: c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\mdcr\5c7639a0\5981344d\App_Web_oja12imh.0.cs Line: 0

Stack Trace:

[FormatException: Invalid character in a Base-64 string.]

   System.Convert.FromBase64String(String s) +0

   System.Web.UI.ObjectStateFormatter.Deserialize(String inputString) +77

   System.Web.UI.ObjectStateFormatter.System.Web.UI.IStateFormatter.Deserialize(String serializedState) +4

   System.Web.UI.Util.DeserializeWithAssert(IStateFormatter formatter, String serializedState) +37

   System.Web.UI.HiddenFieldPageStatePersister.Load() +113

[ViewStateException: Invalid viewstate. 

	Client IP:

	Port: 1486

	User-Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.04506.648; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; InfoPath.3; .NET4.0C; .NET4.0E)


[HttpException (0x80004005): The state information is invalid for this page and might be corrupted.]

   System.Web.UI.ViewStateException.ThrowError(Exception inner, String persistedState, String errorPageMessage, Boolean macValidationError) +106

   System.Web.UI.ViewStateException.ThrowViewStateError(Exception inner, String persistedState) +14

   System.Web.UI.HiddenFieldPageStatePersister.Load() +217

   System.Web.UI.Page.LoadPageStateFromPersistenceMedium() +105

   System.Web.UI.Page.LoadAllState() +43

   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +6785

   System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +242

   System.Web.UI.Page.ProcessRequest() +80

   System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) +21

   System.Web.UI.Page.ProcessRequest(HttpContext context) +49

   ASP.certreviewform_aspx.ProcessRequest(HttpContext context) in c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\mdcr\5c7639a0\5981344d\App_Web_oja12imh.0.cs:0

   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +181

   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +7

I have this problem for the past two days and I am breaking my head. Please let me know how to by pass this error .

I am getting above error I don’t how to solve it please help me.

Delete everything in c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\ and rebuild your solution.

Posted on 10/7/2011 12:15:20 AM by helbin


It is NullReference exception “NullReferenceException:”

Just Chk if trying to convert data which Null.

For example:

Mydata.tostring() will Throw error if Mydata is Null..

Rather use:


Posted on 11/2/2011 05:30:37 AM by Rufix

I have same problem, proposed solution didn’t work for me:P any other ideas?:)

Posted on 3/14/2012 08:17:40 AM by gma

This error is usually caused by the asp worker process or the server recycling. By default, ASP.NET encrypts the viewstate using an Autogenerated Key when the process spins up. The problem comes when a client (browser) sends the request with a viewstate encrypted with the key generated by another worker process. Since the key is different, ASP.NET will not be able to decrypt the viewstate and it will throw the above error.

There are several ways to get around this problem:

  1. Host your site on a server that never restarts or recycles!!! Obviously, this is impossible!

  2. Disable ViewstateMac by putting this ?enableViewStateMac=‘false’? in your web.config. This approach is not 100% secure.

  3. Configure ASP.NET to not use Auto-Generated Key but rather a predefined key. This is the preferred method.

To do this, follow these steps:

a) Either build your own Key Generator (http://support.microsoft.com/kb/313091/EN-US/) or use this tool (http://www.aspnetresources.com/tools/keycreator.aspx). I highly recommend you use the online tool. So assuming you will use the online tool:

b) In the online tool, simply click on ?Generate?.

c) Copy the content in the textbox into your site?s web.config file. The machineKey node should be within <system.web>







validationKey='2EEA416CEFC6D6BE856ED57B97FB9CA7DFA CE17C073125949A1D682C80A44BB2A

D887DDDC13DBFB0954F1000FEE5757E99693F222F8E28CAA2E 6DAB8C4F99E0C'

decryptionKey='877478B2F33A74226ABEF55FDCC1A76E43F 1BBEA6241A592' 

validation='SHA1' />

<compilation debug='false'/>

<authentication mode='Windows'/>

<pages enableViewStateMac='true'/>



For more information on viewstate troubleshooting, see http://support.microsoft.com/default...b;EN-US;829743

Posted on 9/28/2017 02:54:32 PM by Berledys

Ni quiere abrir la plataforma sed cordoba

Posted on 9/5/2018 10:28:22 PM by Andy