getting viewstate error in jmeter

Question

when I am running Jmeter script on my app'(asp.net) and passing viewstate using regexp' I am getting the following error

"231|error|500|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.|"

Then app' is not configured on web farm.

Note: Manually the application works fine.

Answer 1

It looks like that you're missing another mandatory parameter or passing an incorrect viewstate. Perhaps ASP.NET Login Testing with JMeter guide could help.