Validation of viewstate MAC failed.

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ASP.NET

Server Error in '/' Application.

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.

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:


[No relevant source lines]

Source File: c:\windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\root\072db28f\715b52dc\App_Web_qw5tgnj5.7.cs Line: 0

Stack Trace:


[ViewStateException: Invalid viewstate.
Client IP: 117.222.220.26
Port: 4404
Referer: http://academicresult.in/Admin/School.aspx
Path: /Admin/School.aspx
User-Agent: Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.101 Safari/537.36
ViewState: 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...]

[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) +198
System.Web.UI.ObjectStateFormatter.Deserialize(String inputString, Purpose purpose) +432
System.Web.UI.ObjectStateFormatter.System.Web.UI.IStateFormatter2.Deserialize(String serializedState, Purpose purpose) +8
System.Web.UI.Util.DeserializeWithAssert(IStateFormatter2 formatter, String serializedState, Purpose purpose) +40
System.Web.UI.HiddenFieldPageStatePersister.Load() +248
System.Web.UI.Page.LoadPageStateFromPersistenceMedium() +88
System.Web.UI.Page.LoadAllState() +36
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +6704
System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +245
System.Web.UI.Page.ProcessRequest() +72
System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) +21
System.Web.UI.Page.ProcessRequest(HttpContext context) +58
ASP.admin_school_aspx.ProcessRequest(HttpContext context) in c:\windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\root\072db28f\715b52dc\App_Web_qw5tgnj5.7.cs:0
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +341
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +69