Cause: decryption key does not match

Solutions:

a). application pool restart will force generating a new decryption key, fix site problem if application pool restart

b). explicitly specify machine key and decryption key in web.config

c). enable "Load User Profile" from application pool

References:

https://support.microsoft.com/en-us/topic/resolving-view-state-message-authentication-code-mac-errors-6c0e9fd3-f8a8-c953-8fbe-ce840446a9f3

https://learn.microsoft.com/en-US/troubleshoot/developer/webapps/aspnet/health-diagnostic-performance/troubleshooting-view-state-is-invalid-error