Description:

Users get errors on various pages with a referral URL of /Site/Errors/500.aspx. The server Event Viewer contains the content of the detailed error message below.



Steps To Reproduce:

This is due to configuration requirements for a Web Farm. It may occur only after updates (i.e. service pack update) to the ASP.Net framework.



Resolutions:

This resolution is addressed in the following article for setting up load balancing with Project Insight:

http://www.projectinsight.net/community/learn/article/setting-up-load-balancing-or-a-web-farm-with-project-insight.aspx



Affected Versions:

All



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Detailed Error Message

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.

Online 1/4/2010
Updated on: