Validation of viewstate MAC failed (1 Viewer)

[Biffa001]

Trying to connect to the TV server over the net with this error:

Halfway down it says:

[ViewStateException: Invalid viewstate.
Client IP: 5.2.45.107
Port:

Which is not my HTPC's ip at all....

Here's the full error:

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\v2.0.50727\Temporary ASP.NET Files\root\d35413a3\2368fb95\App_Web_mgsnotjs.8.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) +371
System.Web.UI.ObjectStateFormatter.Deserialize(String inputString) +197

[ViewStateException: Invalid viewstate.
Client IP: 5.2.45.107
Port:
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1.7) Gecko/20091221 Firefox/3.5.7
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) +118
System.Web.UI.ViewStateException.ThrowMacValidationError(Exception inner, String persistedState) +12
System.Web.UI.ObjectStateFormatter.Deserialize(String inputString) +227
System.Web.UI.ObjectStateFormatter.System.Web.UI.IStateFormatter.Deserialize(String serializedState) +5
System.Web.UI.Util.DeserializeWithAssert(IStateFormatter formatter, String serializedState) +37
System.Web.UI.HiddenFieldPageStatePersister.Load() +210
System.Web.UI.Page.LoadPageStateFromPersistenceMedium() +107
System.Web.UI.Page.LoadAllState() +43
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5247
System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +247
System.Web.UI.Page.ProcessRequest() +79
System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) +23
System.Web.UI.Page.ProcessRequest(HttpContext context) +110
ASP.default_aspx.ProcessRequest(HttpContext context) in c:\Windows\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\d35413a3\2368fb95\App_Web_mgsnotjs.8.cs:0
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +391
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +76


Version Information: Microsoft .NET Framework Version:2.0.50727.3603; ASP.NET Version:2.0.50727.3074

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