I have a web project that I created in Visual Studio 2010. I originally compiled it in 4.0 but then compiled down to 3.5 so I can deploy it here. Everything works fine locally but when I try to deploy it here I receive the following messages: 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. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.Web.HttpException: 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. I have no problem when I run the application under IIS from my local Host but it will not come up once I deploy to Winhost. Any suggestions ? I'm running windows 2008 sever with IIS 7.0. I suspect something is different between my IIS setting and Winhost's but not sure what?
I suspect your application pool is being recycled. There are several conditions/trhresholds set on the server that will cause a customers application pool to be recycled. When it is recycled the viewstate is lost. If your application doesn't need this feature I suggest you disable viewstate. Here are the conditions that will recycle an application pool by our system. 1) More than 20 minutes of idle time (no http request in 20 minutes) 2) The application uses more than 100 MB memory 3) The application uses more than 70% of CPU for more than 5 minutes
