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.<br><br>See http://go.microsoft.com/fwlink/?LinkID=314055 for more information.

Server Error in '/MeetingSearch' 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.

See http://go.microsoft.com/fwlink/?LinkID=314055 for more information.

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.

See http://go.microsoft.com/fwlink/?LinkID=314055 for more information.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace: 


[ViewStateException: Invalid viewstate. 
	Client IP: 185.112.145.180
	Port: 53782
	Referer: https://stykkisholmur.oneportal.is/MeetingSearch/index.php
	Path: /MeetingSearch/index.php
	User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 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.

See http://go.microsoft.com/fwlink/?LinkID=314055 for more information.]
   System.Web.UI.ViewStateException.ThrowError(Exception inner, String persistedState, String errorPageMessage, Boolean macValidationError) +161
   System.Web.UI.ObjectStateFormatter.Deserialize(String inputString, Purpose purpose) +731
   System.Web.UI.Util.DeserializeWithAssert(IStateFormatter2 formatter, String serializedState, Purpose purpose) +65
   System.Web.UI.HiddenFieldPageStatePersister.Load() +319
   System.Web.UI.Page.LoadPageStateFromPersistenceMedium() +377
   System.Web.UI.Page.LoadAllState() +46
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +9298
   System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +355
   System.Web.UI.Page.ProcessRequest() +79
   System.Web.UI.Page.ProcessRequest(HttpContext context) +74
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +537
   System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) +172
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +93

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.8.9316.0