Validation of viewstate MAC Failed

elmbrook used Ask the Experts™

We have a website that is getting a "Validation of viewstate MAC Failed. If this application is hosted by a Web Farm or Cluster...." error.

The website was created in VS2005 and .Net Framework = 2.0.

It seems that if the user spends a long time on the website without doing anything and then tries to do something this error message is displayed.

I also have this happening on another website which is VS2008 with .Net Framework 3.5

How do I get around this error? Error
Watch Question

Do more with

Expert Office
EXPERT OFFICE® is a registered trademark of EXPERTS EXCHANGE®
Top Expert 2009
Please ensure that Machine key is same on all the servers which constitute to Web Farm.


Do more with

Expert Office
Submit tech questions to Ask the Experts™ at any time to receive solutions, advice, and new ideas from leading industry professionals.

Start 7-Day Free Trial