Here too (on a brand new HP laptop, also Firefox). But it isn't related to the age of your device. > Firefox Can’t Open This Page > To protect your security,

Here too (on a brand new HP laptop, also Firefox). But it isn't related to the age of your device. > Firefox Can’t Open This Page > To protect your security, www.youtube.com will not allow Firefox to display the page if another site has embedded it. To see this page, you need to open it in a new window. > https://support.mozilla.org/en-US/kb/xframe-neterror-page?as=u&utm_source=inproduct https://support.mozilla.org/en-US/kb/xframe-neterror-page?as... Which says > If you see this error, it is usually caused by a misconfigured website that is trying to display another website without the consent of its owner. > Websites can use x-frame options or a content security policy to control if other websites may embed them on their own pages. This is an important security feature to prevent clickjacking, which is an attack that allows malicious sites to trick users into clicking links on a site. Generally speaking this kind of situation represents the opposite problem to what the OP describes: the web browsers themselves are constantly changing and breaking previously working websites. This imposes a burden of continuously modify the websites to comply with the latest and greatest APIs; most of the web isn't going to upgrade and will slowly rot (like happened with sites that relied on Flash, a proprietary, non-standard plugin). Obsolete devices - the theme of this post - aren't a moving target like the web is. Now, for this particular website, being a 2021 course, it's just a bug. It _should_ just be fixed and set the proper CSP.