Hello friends,

I have uploaded YAF-v1.9.5-RC1-BIN on my domain it works fine for all features but when i try to register new member it shows the following error.

Server Error in Application.

Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that 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 configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.

Can anybody guide to solve this error.

Thanks in advance.

You need to add a machinekey to your webconfig

http://www.orcsweb.com/articles/aspnetmachinekey.aspx 

Additionally, that is an old version, and a beta at that. You may want to use a more current version of YAF, as many bugs are resolved as YAF moves forward.

The issue your having comes from your application shutting down during a member's registration - when it restarts, the viewstate is re-encrypted with new keys. Search here for machineKey and decryptionKey as tha_watcha suggested -- that will help with the timeout issues causing new encryption.

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