anti-forgery token could not be decrypted

http://www.naveen.com.au/asp-net/anti-forgery-token-could-not-be-decrypted/1364

Solution:

1. Create a Machine Key from this site http://aspnetresources.com/tools/machineKey
2. Add the Machine key in the Web.config in your Website(s) under .. for example:
[xml]
<system.web>
<machineKey validationKey="21F090935F6E49C2C797F69BBAAD8402ABD2EE0B667A8B44EA7DD4374267A75D7AD972A119482D15A4127461DB1DC347C1A63AE5F1CCFAACFF1B72A7F0A281B"
decryptionKey="ABAA84D7EC4BB56D75D217CECFFB9628809BDB8BF91CFCD64568A145BE59719F" validation="SHA1" decryption="AES" />
</system.web>
[/xml]

Thats it .