Mojoportal error when login or do an action example search, register,

I download code mojoportal 2.4.1.0 and i run it on Visual Studio 2013 it work correctly. But when i click and do an action for example login/register, search it error as bellow message: Can you help me solution to this problem thank for help

Server Error in '/' Application. Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that 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 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.

[ViewStateException: Invalid viewstate. 
    Client IP: ::1
    Port: 54462
    Referer: http://localhost:50434/Secure/Register.aspx?returnurl=%2f
    Path: /Default.aspx
    User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36
    ViewState: ynW4HTBG+LP2gNvL8oM93542YrBJSRaZ/upI3Nd3sZF55f3jwSJh8Z/TpPbcZVPYaTLQg0wGkT/yvGoBfBlF26veXaeQitMbk0VZcbrDgfZcFzZAnNgjRTX2jnYP8Akp

[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) +116
   System.Web.UI.ObjectStateFormatter.Deserialize(String inputString, Purpose purpose) +425
   System.Web.UI.ObjectStateFormatter.System.Web.UI.IStateFormatter2.Deserialize(String serializedState, Purpose purpose) +13
   System.Web.UI.Util.DeserializeWithAssert(IStateFormatter2 formatter, String serializedState, Purpose purpose) +40
   System.Web.UI.HiddenFieldPageStatePersister.Load() +248
   System.Web.UI.Page.LoadPageStateFromPersistenceMedium() +251
   System.Web.UI.Page.LoadAllState() +36
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +6569
   System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +245
   System.Web.UI.Page.ProcessRequest() +72
   System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) +22
   System.Web.UI.Page.ProcessRequest(HttpContext context) +58
   ASP.default_aspx.ProcessRequest(HttpContext context) in c:\Users\thanhnt26\AppData\Local\Temp\Temporary ASP.NET Files\root\059989a4\a89b30e8\App_Web_21zdcssy.18.cs:0
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +188
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +69