ASP.NET MVC Validation of ViewState MAC failed

Posted by Kevin Pang on Stack Overflow See other posts from Stack Overflow or by Kevin Pang
Published on 2009-09-01T00:46:59Z Indexed on 2010/05/21 22:50 UTC
Read the original article Hit count: 431

Filed under:

asp.net-mvc

After publishing a new build of my ASP.NET MVC web application, I often see this exception thrown when browsing to the site:

System.Web.Mvc.HttpAntiForgeryException: A required anti-forgery token was not supplied or was invalid. ---> 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. ---> System.Web.UI.ViewStateException: Invalid viewstate.

This exception will continue to occur on each page I visit in my web application until I close out of Firefox. After reopening Firefox, the site works perfectly. Any idea what's going on?

Additional notes:

I am not using any ASP.NET web controls (there are no instances of runat="server" in my application)
If I take out the <%= Html.AntiForgeryToken %> from my pages, this problem seems to go away

Related posts about asp.net-mvc

Migrating ASP.NET MVC 1.0 applications to ASP.NET MVC 2 RTM

as seen on ASP.net Weblogs - Search for 'ASP.net Weblogs'
Note: ASP.NET MVC 2 RTM isn’t yet released! But this tool will help you get your ASP.NET MVC 1.0 applications ready for when it is! I have updated the MVC App Converter to convert projects from ASP.NET MVC 1.0 to ASP.NET MVC 2 RTM. This should be last the last major change to the MVC App Converter… >>> More
ASP.NET MVC 3 Hosting :: New Features in ASP.NET MVC 3

as seen on Geeks with Blogs - Search for 'Geeks with Blogs'
Razor View Engine The Razor view engine is a new view engine option for ASP.NET MVC that supports the Razor templating syntax. The Razor syntax is a streamlined approach to HTML templating designed with the goal of being a code driven minimalist templating approach that builds on existing C#, VB… >>> More
PathTooLongException after migrating from ASP.NET MVC 1 to ASP.NET MVC 2

as seen on Stack Overflow - Search for 'Stack Overflow'
I had updated my app from MVC 1 to MVC 2. After that some pages throws PathTooLongException: [PathTooLongException: The specified path, file name, or both are too long. The fully qualified file name must be less than 260 characters, and the directory name must be less than 248 characters.] … >>> More
Differece between Asp.net MVC 1 and Asp.net MVC 2

as seen on Stack Overflow - Search for 'Stack Overflow'
what is differece between Asp.net MVC 1 and Asp.net MVC 2? >>> More
Top 5 reasons for using ASP.NET MVC 2 rather than ASP.NET MVC 1

as seen on Stack Overflow - Search for 'Stack Overflow'
I've been using ASP.NET MVC 1 for a while now, and am keen to take advantage of the improvements in MVC 2. Things like validation seem greatly improved, and strongly-typed HTML helper methods look great. So, for those of you who have real-world practical experience of using ASP.NET MVC 1 and are… >>> More

Developer IT