Este erro ja esta me tirando do serio com a Microsoft. Alguem consegue me ajudar?
Ja decorei o Google e nao achei a solução.
System.Web.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: Invalid viewstate.
Client IP: 177.221.110.150
Port: 19337
Referer: http://sga.grupobbm.com.br/sga/WFORM_LOGIN.aspx?ReturnUrl=%2fsga%2fsistema%2fwform_principal.aspx
Path: /sga/WFORM_LOGIN.aspx
User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:37.0) Gecko/20100101 Firefox/37.0
ViewState: /wEPDwUKMTQ2MTU3MDM5MA9kFgICBA9kFgQCAQ8WAh4Fc3R5bGUFDmRpc3BsYXk6YmxvY2s7ZAIDDxYCHwAFDmRpc3BsYXk6YmxvY2s7ZGQbhDaTQ9+QPubO3+YmUpZPnHdv8xq4VBPI8FLcaiO6Zw==
at System.Web.UI.ViewStateException.ThrowError(Exception inner, String persistedState, String errorPageMessage, Boolean macValidationError)
at System.Web.UI.ObjectStateFormatter.Deserialize(String inputString, Purpose purpose)
at System.Web.UI.ObjectStateFormatter.System.Web.UI.IStateFormatter2.Deserialize(String serializedState, Purpose purpose)
at System.Web.UI.Util.DeserializeWithAssert(IStateFormatter2 formatter, String serializedState, Purpose purpose)
at System.Web.UI.HiddenFieldPageStatePersister.Load()
at System.Web.UI.Page.LoadPageStateFromPersistenceMedium()
at System.Web.UI.Page.LoadAllState()
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest()
at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context)
at System.Web.UI.Page.ProcessRequest(HttpContext context)
at ASP.wform_login_aspx.ProcessRequest(HttpContext context)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
Hellmann's (Joviano Pott)