Issue symptoms
When one of your customers or agents attempts to sign into the Zendesk customer portal, they receive the following error message: Forbidden Invalid authenticity token.
Resolution steps
This error is likely caused by a corrupted cookie in your browser. Complete the following troubleshooting steps:
- Disable any anti-tracking or security software.
- Clear your cache and cookies and attempt to sign in again.
- If that does not resolve the issue, ensure third-party cookies are enabled in the browser.