Validation of viewstate MAC failed.

Question

Hello friends I have uploaded my web site on my domain it works fine for all features but when i load my view data page data i can see but if i leave that page idle for some time(20 min) and then refersh the page that time error is coming.   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.   suggest me some solution. thank you!!!

Rajeesh Menoth · Answer

Hi Try this code.. Web config : false enableEventValidation= false viewStateEncryptionMode= Never enableViewStateMac= false > or SHA1 validationKey=A1B2C3D4E5F6F6E5D4C3B2A1A1B2C3D4E5F6F6E5D4C3B2 A1A1B2C3D4E5F6F6E5D4C3B2A1A1B2C3D4E5F6F6E5D4C3B2A1 A1B2C3D4E5F6F6E5D4C3B2A1B2C3D4E5 decryption= Auto decryptionKey= A1B2C3D4E5F6F6E5D4C3B2A1A1B2C3D4E5F6F6E5D4C3B2A1 /> Reference : https://rajeeshmenoth.wordpress.com/2014/05/20/validation-of-viewstate-mac-failed-in-asp-net/

Rajeesh Menoth · Answer

Hi Shivani Welcome :) The answer is helpful. Then please accept it ..!!

Shivani Gupta · Answer

thank you all... this problem now solved  i wrote in web config file .now it's working fine.

Vinay Singh · Answer

Hi You just need to add the below configuration in you web.config file