I use visual Studio 2005 and build a web application and it is running at customer server from 2010.
My problem is when I try to run it from Code in visual studio 2005
the login page shown and when I click the login button the following error occurred.
" 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".
Please help me ASAP to solve this issue.