Validation of viewstate MAC failed

[primagic]

Someone help please

I keep getting this error message:

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: 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.

Source Error:

The source code that generated this unhandled exception can only be shown when compiled in debug mode. To enable this, please follow one of the below steps, then request the URL:

1. Add a "Debug=true" directive at the top of the file that generated the error. Example:

  <%@ Page Language="C#" Debug="true" %>

or:

2) Add the following section to the configuration file of your application:

<configuration>
   <system.web>
       <compilation debug="true"/>
   </system.web>
</configuration>

Note that this second technique will cause all files within a given application to be compiled in debug mode. The first technique will cause only that particular file to be compiled in debug mode.

Important: Running applications in debug mode does incur a memory/performance overhead. You should make sure that an application has debugging disabled before deploying into production scenario.

Stack Trace:

[HttpException (0x80004005): Unable to validate data.]
   System.Web.Configuration.MachineKeySection.GetDecodedData(Byte[] buf, Byte[] modifier, Int32 start, Int32 length, Int32& dataLength) +289
   System.Web.UI.ObjectStateFormatter.Deserialize(String inputString) +140

[ViewStateException: Invalid viewstate. 
	Client IP: 87.194.184.226
	Port: 54723
	User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-GB; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3 ( .NET CLR 3.5.30729)
	ViewState: /wEPDwUJNzAzNDY0MDY2ZGRtkf5XziYhqdNEgAurJOMXrpvVGQ==
	Referer: [URL unfurl="true"]http://www.primagic.co.uk/contact.aspx[/URL]
	Path: /contact.aspx]

[HttpException (0x80004005): 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.]
   System.Web.UI.ViewStateException.ThrowError(Exception inner, String persistedState, String errorPageMessage, Boolean macValidationError) +106
   System.Web.UI.ViewStateException.ThrowMacValidationError(Exception inner, String persistedState) +14
   System.Web.UI.ObjectStateFormatter.Deserialize(String inputString) +242
   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() +207
   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.contact_aspx.ProcessRequest(HttpContext context) +37
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +181
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +75

 

[ca8msm]

OK, so what happened when you followed the instructions in the error message?

Mark,

Darlington Web Design[tab]|[tab]Experts, Information, Ideas & Knowledge[tab]|[tab]ASP.NET Tips & Tricks

 

[primagic]

same error

 

[ca8msm]

You'll need to provide more information such as the setup of your server, what you've tried so far etc. Simply posting an error message doesn't give us a lot to go on...

Mark,

Darlington Web Design[tab]|[tab]Experts, Information, Ideas & Knowledge[tab]|[tab]ASP.NET Tips & Tricks

 

[primagic]

i am controlling the websites using plesk

if i uninstall plesk and use iis then they work fine. I have tried adding machine keys and so on to the web.config file but still no luck

 

[ca8msm]

OK, if the site works fine without plesk, then it's something that their product is doing to change the state of the environment. I'd suggest going to their support section, see if they have anything on their knowledgebase and if not creating a support ticket with them.

Mark,

Darlington Web Design[tab]|[tab]Experts, Information, Ideas & Knowledge[tab]|[tab]ASP.NET Tips & Tricks