This error can be due to a corrupted cookie in your browser. Clear your browser's cache and cookies, restart the browser and try to log in.
If the error remains, the problem is that your browser has blocked any cookies from the Support Portal.
Go through the following steps resolve this error:
- In the top right of your browser, click the three dots and then Settings
- At the bottom, click on Advanced.
- In the Privacy and Security section, click Site settings
- Select Cookies
- Uncheck the box next to Block third-party cookies and site data
- Alternatively, you can leave “Block third-party cookies and site data” enabled and add "grammatech.zendesk.com" in the Allow list