Invalid_Viewstate - Please help!

[InnoCreate]

Hi Everyone,
Occasionally i'm getting the following error logged. I've heard this
can be caused by proxy servers. Does anyone know anyways to resolve the
issue or anything else that could cause the issue.

Thanks
James

[Error]

System.Web.HttpUnhandledException: Exception of type
System.Web.HttpUnhandledException was thrown. --->
System.Web.HttpException: Invalid_Viewstate
Client IP: 88.105.241.198
Port: 2352
User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;
SV1; .NET CLR 1.1.4322)
ViewState:
dDwtNjc4MDAyODQ1O3Q8O2w8aTwzPjs+O2w8dDw7bDxpPDE+Oz 47bDx0PEAwPHA8cDxsPERhdGFLZXlzO18hSXRlbUNvdW50Oz47 bDxsPD47aTwxPjs+Pjs+Ozs7Ozs7Ozs+O2w8aTwwPjs+O2w8dD w7bDxpPDE+O2k8Mz47aTw1PjtpPDc+O2k8OT47aTwxMD47Pjts PHQ8cDxwPGw8SW1hZ2VVcmw7TmF2aWdhdGVVcmw7PjtsPC4uL1 Byb3BlcnR5SW1hZ2VzLzgyLTNfdGh1bWIuanBnOy4uL0hvbWVC dXllcnMvUHJvcGVydHlWaWV3LmFzcHg/UHJvcGVydHlJRD04Mjs+Pjs+Ozs+O3Q8cDxwPGw8TmF2aWdhdG VVcmw7PjtsPC4uL0hvbWVCdXllcnMvUHJvcGVydHlWaWV3LmFz cHg/UHJvcGVydHlJRD04Mjs+Pjs+O2w8aTwwPjs+O2w8dDxAPEFza2 luZyBQcmljZSDCozQwMCwwMDA7Pjs7Pjs+Pjt0PHA8cDxsPE5h dmlnYXRlVXJsOz47bDwuLi9Ib21lQnV5ZXJzL1Byb3BlcnR5Vm lldy5hc3B4P1Byb3BlcnR5SUQ9ODI7Pj47PjtsPGk8MD47Pjts PHQ8QDw0Oz47Oz47Pj47dDxwPHA8bDxOYXZpZ2F0ZVVybDs+O2 w8Li4vSG9tZUJ1eWVycy9Qcm9wZXJ0eVZpZXcuYXNweD9Qcm9w ZXJ0eUlEPTgyOz4+Oz47bDxpPDA+Oz47bDx0PEA8SG91c2U7Pj s7Pjs+Pjt0PHA8cDxsPE5hdmlnYXRlVXJsOz47bDwuLi9Ib21l QnV5ZXJzL1Byb3BlcnR5Vmlldy5hc3B4P1Byb3BlcnR5SUQ9OD I7Pj47PjtsPGk8MD47PjtsPHQ8QDxQbGFjZSBhIEZSRUUgYWQg Tk9XIHNlZSBIb21lIHNlbGxlcnMgcGFnZTs+Ozs+Oz4+O3Q8QD wuLi9Ib21lQnV5ZXJzL1Byb3BlcnR5Vmlldy5hc3B4P1Byb3Bl cnR5SUQ9ODI7RnJvbnQgUGFnZSBBZHZlcnQgZm9yIFlvdXIgUH JvcGVydHkhOz47Oz47Pj47Pj47Pj47Pj47Pvd76txaNLSVFxPk S2M3/7tMO/GQ
Http-Referer:
http://www.homester.co.uk/(iuenpv55q...OVMTC=standard
Path: /Index.aspx. ---> System.Web.HttpException:
Authentication of viewstate failed. 1) If this is a cluster, edit
<machineKey> configuration so all servers use the same validationKey
and validation algorithm. AutoGenerate cannot be used in a cluster.
2) Viewstate can only be posted back to the same page. 3) The
viewstate for this page might be corrupted. --->
System.Web.HttpException: Unable to validate data.
at System.Web.Configuration.MachineKey.GetDecodedData (Byte[] buf,
Byte[] modifier, Int32 start, Int32 length, Int32& dataLength)
at System.Web.UI.LosFormatter.Deserialize(String input)
--- End of inner exception stack trace ---
at System.Web.UI.LosFormatter.Deserialize(String input)
at System.Web.UI.Page.LoadPageStateFromPersistenceMed ium()
--- End of inner exception stack trace ---
at System.Web.UI.Page.LoadPageStateFromPersistenceMed ium()
at System.Web.UI.Page.LoadPageViewState()
at System.Web.UI.Page.ProcessRequestMain()
--- End of inner exception stack trace ---
at System.Web.UI.Page.HandleError(Exception e)
at System.Web.UI.Page.ProcessRequestMain()
at System.Web.UI.Page.ProcessRequest()
at System.Web.UI.Page.ProcessRequest(HttpContext context)
at
System.Web.CallHandlerExecutionStep.System.Web.Htt pApplication+IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionS tep step,
Boolean& completedSynchronously

[DWS]

InnoCreate,
A little bit too much info on this post. Next time change ip to 192.168.1.1

Yes this could be caused by a proxy server but you'd probably
also have errors like user A can see user b's web pages.

I sometimes get errors like this when developing and I change the page while
its
still running in another browser, when controls that are created on the fly
aren't
available on the server when the viewstate is checked by asp.net, when using
the
restart button in visual studio (thats same as still running in another
browser)

Look for someone making changes outside a move to production cycle
Look for someone debugging on the production server.
Look for controls that are created on the fly.

Good Luck
DWS
"InnoCreate" wrote:

Hi Everyone,
Occasionally i'm getting the following error logged. I've heard this
can be caused by proxy servers. Does anyone know anyways to resolve the
issue or anything else that could cause the issue.

Thanks
James

[Error]

System.Web.HttpUnhandledException: Exception of type
System.Web.HttpUnhandledException was thrown. --->
System.Web.HttpException: Invalid_Viewstate
Client IP: 88.105.241.198
Port: 2352
User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;
SV1; .NET CLR 1.1.4322)
ViewState:
dDwtNjc4MDAyODQ1O3Q8O2w8aTwzPjs+O2w8dDw7bDxpPDE+Oz 47bDx0PEAwPHA8cDxsPERhdGFLZXlzO18hSXRlbUNvdW50Oz47 bDxsPD47aTwxPjs+Pjs+Ozs7Ozs7Ozs+O2w8aTwwPjs+O2w8dD w7bDxpPDE+O2k8Mz47aTw1PjtpPDc+O2k8OT47aTwxMD47Pjts PHQ8cDxwPGw8SW1hZ2VVcmw7TmF2aWdhdGVVcmw7PjtsPC4uL1 Byb3BlcnR5SW1hZ2VzLzgyLTNfdGh1bWIuanBnOy4uL0hvbWVC dXllcnMvUHJvcGVydHlWaWV3LmFzcHg/UHJvcGVydHlJRD04Mjs+Pjs+Ozs+O3Q8cDxwPGw8TmF2aWdhdG VVcmw7PjtsPC4uL0hvbWVCdXllcnMvUHJvcGVydHlWaWV3LmFz cHg/UHJvcGVydHlJRD04Mjs+Pjs+O2w8aTwwPjs+O2w8dDxAPEFza2 luZyBQcmljZSDCozQwMCwwMDA7Pjs7Pjs+Pjt0PHA8cDxsPE5h dmlnYXRlVXJsOz47bDwuLi9Ib21lQnV5ZXJzL1Byb3BlcnR5Vm lldy5hc3B4P1Byb3BlcnR5SUQ9ODI7Pj47PjtsPGk8MD47Pjts PHQ8QDw0Oz47Oz47Pj47dDxwPHA8bDxOYXZpZ2F0ZVVybDs+O2 w8Li4vSG9tZUJ1eWVycy9Qcm9wZXJ0eVZpZXcuYXNweD9Qcm9w ZXJ0eUlEPTgyOz4+Oz47bDxpPDA+Oz47bDx0PEA8SG91c2U7Pj s7Pjs+Pjt0PHA8cDxsPE5hdmlnYXRlVXJsOz47bDwuLi9Ib21l QnV5ZXJzL1Byb3BlcnR5Vmlldy5hc3B4P1Byb3BlcnR5SUQ9OD I7Pj47PjtsPGk8MD47PjtsPHQ8QDxQbGFjZSBhIEZSRUUgYWQg Tk9XIHNlZSBIb21lIHNlbGxlcnMgcGFnZTs+Ozs+Oz4+O3Q8QD wuLi9Ib21lQnV5ZXJzL1Byb3BlcnR5Vmlldy5hc3B4P1Byb3Bl cnR5SUQ9ODI7RnJvbnQgUGFnZSBBZHZlcnQgZm9yIFlvdXIgUH JvcGVydHkhOz47Oz47Pj47Pj47Pj47Pj47Pvd76txaNLSVFxPk S2M3/7tMO/GQ Http-Referer:
http://www.homester.co.uk/(iuenpv55q...OVMTC=standard
Path: /Index.aspx. ---> System.Web.HttpException:
Authentication of viewstate failed. 1) If this is a cluster, edit
<machineKey> configuration so all servers use the same validationKey
and validation algorithm. AutoGenerate cannot be used in a cluster.
2) Viewstate can only be posted back to the same page. 3) The
viewstate for this page might be corrupted. --->
System.Web.HttpException: Unable to validate data.
at System.Web.Configuration.MachineKey.GetDecodedData (Byte[] buf,
Byte[] modifier, Int32 start, Int32 length, Int32& dataLength)
at System.Web.UI.LosFormatter.Deserialize(String input)
--- End of inner exception stack trace ---
at System.Web.UI.LosFormatter.Deserialize(String input)
at System.Web.UI.Page.LoadPageStateFromPersistenceMed ium()
--- End of inner exception stack trace ---
at System.Web.UI.Page.LoadPageStateFromPersistenceMed ium()
at System.Web.UI.Page.LoadPageViewState()
at System.Web.UI.Page.ProcessRequestMain()
--- End of inner exception stack trace ---
at System.Web.UI.Page.HandleError(Exception e)
at System.Web.UI.Page.ProcessRequestMain()
at System.Web.UI.Page.ProcessRequest()
at System.Web.UI.Page.ProcessRequest(HttpContext context)
at
System.Web.CallHandlerExecutionStep.System.Web.Htt pApplication+IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionS tep step,
Boolean& completedSynchronously

[MADCookie]

All my company's web applications live in a web farms. It is recommended that you set the <machineKey> in the web.config and not use the autosettings. I let the references speak for themselves as to the magic it does.

I set the <machineKey> in my web.config file and have never had a problem. It is very easy to do. The hardest part was coming up with the extremely long validationKey and decryptionKey.

Hope this helps.

References
From Microsoft:
http://msdn.microsoft.com/library/de...keysection.asp

Real world example:
http://www.hanselman.com/blog/Commen...f08a9a5f5.aspx

System.Web.HttpException:
Authentication of viewstate failed. 1) If this is a cluster, edit
<machineKey> configuration so all servers use the same validationKey
and validation algorithm. AutoGenerate cannot be used in a cluster.
2) Viewstate can only be posted back to the same page. 3) The
viewstate for this page might be corrupted. --->