the firefox and Netscape plugin NPAPI (2019-09-25) .MSI download link does not work. Please fix
If you're downloading these under a redistribution agreement and logging into your account to access them, the links are dynamically generated. When it breaks, it's usually a stale cookie. You might try it in incognito mode. I'm happy to mention it to the distribution team, but it would be helpful to know where you are geographically. All of this stuff exists on a CDN, and we're not getting widespread reports of this. I imagine it's a relatively localized problem.