Fixing Validation of viewstate MAC failed issue

Some customers reported Validation of viewstate MAC failed issue after upgrading their on-premise environments to KanBo 2.2 version.


Server Error in '/' Application.


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.


Following solution is not recommended for production environments - you should install ASP.NET KB 2905247 update instead.


kanbo Fixing Validation of viewstate MAC failed issue


You can solve this issue by adding <pages> element in the web.config, like this:

<configuration>  
 <system.web>     
  <pages enableViewStateMac="false" />  
 </system.web>
</configuration>


kanbo Fixing Validation of viewstate MAC failed issue


cluster EnableViewStateMac MAC machineKey validationKey

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