Hello, I have a problem with firefox and it's recently unable to open Google and Youtube due to HTTP Strict Transport Security (HSTS) with an error Code : SEC_ERROR_UNKNOWN_ISSUER I have done the steps in here : https://support.mozilla.org/en-US/kb/error-codes-secure-websites I don't have any third-party Antivirus I have also do about:config security.enterprise_roots.enabled by changing to true. It works but unfortunately youtube is broken when i set it to true. I can't also accept the risk and continue since there's no button that says it. Thank you