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Validation of viewstate MAC Failed

elmbrook asked
Last Modified: 2012-05-09

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
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