You get this error when running your application using the Safari browser for the Apple Macintosh:
Validation of viewstate MAC failed.
The state information is invalid for this page and might be corrupted.
Edit your application’s Web.config file to include this line:
<pages validateRequest="false" enableEventValidation="false" viewStateEncryptionMode ="Never" />
Part IX: Troubleshooting Applications
Application Runs But No Data is Displayed