我也是：
Server Error in '/' Application.
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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\v2.0.50727\Temporary ASP.NET Files\root\72206880\8e86270\App_Web_xklyvh1t.18.cs Line: 0
Stack Trace:
[HttpException (0x80004005): Unable to validate data.]
System.Web.Configuration.MachineKeySection.GetDecodedData(Byte[] buf, Byte[] modifier, Int32 start, Int32 length, Int32& dataLength) +294
System.Web.UI.ObjectStateFormatter.Deserialize(String inputString) +203
[ViewStateException: Invalid viewstate.
Client IP: 218.81.220.254
Port: 17184
User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; InfoPath.2; .NET CLR 2.0.50727; MAXTHON 2.0)
ViewState: /wEPDwUKLTUxMTcwNzgxMGRkFqFge3MnJq0KDSRvZm1P9iVXT54=
Referer:
http://www.5iplus.cn/Admin/index.aspx Path: /Admin/index.aspx]
[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) +267
System.Web.UI.ObjectStateFormatter.Deserialize(String inputString) +282
System.Web.UI.ObjectStateFormatter.System.Web.UI.IStateFormatter.Deserialize(String serializedState) +4
System.Web.UI.Util.DeserializeWithAssert(IStateFormatter formatter, String serializedState) +37
System.Web.UI.HiddenFieldPageStatePersister.Load() +198
System.Web.UI.Page.LoadPageStateFromPersistenceMedium() +83
System.Web.UI.Page.LoadAllState() +35
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +7350
System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +213
System.Web.UI.Page.ProcessRequest() +86
System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) +18
System.Web.UI.Page.ProcessRequest(HttpContext context) +49
ASP.admin_index_aspx.ProcessRequest(HttpContext context) in c:\windows\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\72206880\8e86270\App_Web_xklyvh1t.18.cs:0
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +358
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +64
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Version Information: Microsoft .NET Framework Version:2.0.50727.1433; ASP.NET Version:2.0.50727.1433