Server Error: Validation of viewstate MAC failed
Posted by Robert Joseph on 02 March 2020 10:06 AM
Some users experienced this specific "viewstate" error when changing windows or tabs. There are a few technical reasons for the issue. If you do experience this "viewstate" error, we have a few steps for your to follow.
Figure 1: Screenshot of the error.
The quickest way to resolve the issue is deleting the cookies from the EIOBoard site then logging back into the website.
For Chrome users
For Firefox users
There is a shortcut to delete the cookies for a website within the Lock icon.
For Internet Explorer users
The only option is to delete all site cookies. There is no option to delete one site's cookies.
The web application stores a session token that does not always validate against the machine key of the intended web server. We will make the appropriate accommodations in the near future.
Details in the body of the Error:
Server Error in '/EIOBoard' Application. Validation of viewstate MAC failed. If this application is hosted by a Web Farm or AutoGenerate cannot be used in a cluster. See http://go.microsoft.com/fwIink/?LinkID=314055 for more information. Description: An unhandled exception occurred during the execution of the current web reauest. Please review the stack trace for more information about Exception Details: System .Web_HttpException: Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that er See httpwgo.microsoft.com/fwink/?LinklD=314055 for more informaton.
Error: An unhandled generated during the regarding the origin the Stack Trace: [ViewStateException: Invalid viewstate. Client IP: Port: 52189 Referrer: https : Path: /EIOBoard/Login.aspx User-Agent: Mozilla (KHTML, like ViewState: [HttpException (Ox8æø4æ5): Validation of viewstate failed. If this application is hosted