Error : Validation of viewstate MAC failed

If you get the error following error in your .NET app -

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.

Please follow these instructions to resolve it.

Visit http://aspnetresources.com/tools/machineKey and generate a machine key.

Place the key into your web.config within the  node (do not use the key below) e.g.

validationKey='2EEA416CEFC6D6BE856ED57B97FB9CA7DFA CE17C073125949A1D682C80A44BB2A
D887DDDC13DBFB0954F1000FEE5757E99693F222F8E28CAA2E 6DAB8C4F99E0C'
decryptionKey='877478B2F33A74226ABEF55FDCC1A76E43F 1BBEA6241A592'
validation='SHA1' />

Close your browser and reload your website to test.

  • 10 Users Found This Useful
Was this answer helpful?

Related Articles

Setting read and write permissions on files and folders (Windows)

On our Windows hosting file/folder read and write permissions are set by using the file manager...

Enabling detailed error reporting on Windows Server (IIS7)

Windows Server 2008 (IIS7) by default displays non-detailed error messages. This is important for...

Justification for additional IP addresses

Due to the now limited number of IPs in the IP4 address space, the IP Authorities of different...

How to send email using ASP and CDOSYS

The following ASP script can be used to send email using CDOSYS on our servers. Dim iConfig Dim...

Can I view my site before the DNS has propagated?

Windows Hosting All websites are issued with an Instant alias based on the domain you supply...