Some users have begun encountering an "Invalid Authenticity Token" error when they attempt to click Sign in on this website (support.syniti.com). In each case, the issue has been resolved by enabling 3rd-party cookies or disabling browser extensions.
Enable 3rd-party cookies: https://support.google.com/accounts/answer/61416?hl=en
Disable browser extensions: https://support.google.com/chrome_webstore/answer/2664769?hl=en
Microsoft Edge (Chromium)
Enable 3rd-party cookies: https://support.apple.com/guide/safari/manage-cookies-and-website-data-sfri11471/14.0/mac/11.0
Disable browser extensions: https://support.apple.com/guide/safari/get-extensions-sfri32508/14.0/mac/11.0