Article ID: 124306, created on Jan 27, 2015, last review on Jan 27, 2015

  • Applies to:
  • Plesk Automation 11.5

Symptoms

After attempt to refresh website page following error appears:

Error message or request description : Server Error in '/' Application.

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.

See http://go.microsoft.com/fwlink/?LinkID=314055 for more information.

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 <machineKey> configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.

Cause

Application pool work process was shutting down due inactivity.

Resolution

  1. Open IIS.

  2. Click on application pools node.

  3. Locate your web application's application pool.

  4. Right-click and select Advanced Settings.

  5. Set the Idle Time-out(minutes) property.

You can find additional information about ASP.Net life cycle in MSDN article

Search Words

Application pool worker process

Application pool idle timeout

Validation of viewstate MAC failed

33a70544d00d562bbc5b17762c4ed2b3 caea8340e2d186a540518d08602aa065 e0aff7830fa22f92062ee4db78133079

Email subscription for changes to this article
Save as PDF