Question

我们有 ASP.NET 4.0 网络正在 Windows Server 2008 R2 （安装在Amazon ec2实例上）。我们的用户时不时会收到如下错误：

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: System.Web

StackTrace:    
at System.Web.UI.ViewStateException.ThrowMacValidationError(Exception inner, String persistedState)
at System.Web.UI.ObjectStateFormatter.Deserialize(String inputString)
at System.Web.UI.ScriptManager.LoadHistoryState(String serverState)
at System.Web.UI.ScriptManager.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
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.ProcessRequest(HttpContext context)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

TargetSite: Void ThrowMacValidationError(System.Exception, System.String)

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. ---> System.Web.UI.ViewStateException: Invalid viewstate. 
Client IP: Some IP
Port: 49314
Referer: http://www.xxxx.com/xxxxxxx
Path: /xxxxxxx
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/33.0.1750.154 Safari/537.36
ViewState: /wEXAQUMVmVyUHJvZHVjdG9zBQxQVkQgQVNDIzQjMTCkifeeYf3AT+qOX2HL/wiZX7nF6E2sPjS/OhlzF+pfNg==

at System.Web.UI.ViewStateException.ThrowMacValidationError(Exception inner, String persistedState)
at System.Web.UI.ObjectStateFormatter.Deserialize(String inputString)
at System.Web.UI.ScriptManager.LoadHistoryState(String serverState)
at System.Web.UI.ScriptManager.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
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.ProcessRequest(HttpContext context)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

我们已经找到了解决方案，但似乎没有任何效果。我们添加了一个机器密钥，也出现了错误。当我们移动到EC2时，这个错误开始出现。在我们自己的旧专用服务器上没有问题。

注意：设置enableEventValidation =“false”不是一个选项。

Answer 1

这通常在您创建动态控件时发生，并且每次重新创建时都不会设置相同的ID（我希望每次使用Page_Init重新创建它们）。问题的另一个原因可能是当您修改服务器上的某些控件时（例如，清除控件容器），但此更改不会传递到客户端（即，它发生在部分回发期间）。下次页面被POST时，客户端将发送视图状态并控制服务器上不存在的值（例如，输入）。因此，在页面中查找此类逻辑和/或尝试禁用AJAX以查看是否存在差异。

另一种选择是尽可能多地禁用ViewState，但很少需要它。

另一个选择是将ViewState存储在服务器而不是隐藏字段中。

Answer 2

正如@rdmptn所说，这种情况背后有很多原因。其中一个是应用程序池回收。如果用户在网站上忙碌并且应用程序池被回收，那么服务器将找不到回发的viewstate / session并抛出错误。这通常发生在我们没有明确提供机器时。

所以解决方案是在web.config中提供机器密钥。＆LT; machinekey validationkey =＆＃34; xxx＆＃34; decryptionkey =＆＃34; XXX＆＃34;验证=＆＃34; SHA1＆＃34;解密=＆＃34; AES＆＃34; /＆GT;

有关详细信息，请查看http://www.codeproject.com/Questions/464873/Validation-of-viewstate-MAC-failed

您可以从以下网址生成机器密钥

http://aspnetresources.com/tools/machineKey

并将该machinekey元素放在web.config

中

遇到＆＃34;验证视图状态MAC失败＆＃34;

2 个答案: