[zalebz]

in my case I had to copy the link and paste into a fresh tab as clicking actually caused firefox (nightly) to block the install with a message: "news.ycombinator.com - Nightly prevented this site from asking you to intsall software on your computer"

[dooop]

Doesn't work for me. Not sure if a user.js alteration is blocking the fix or what...but I don't want to (even temp) remove it and I certainly don't feel like going through all those prefs to figure out the issue.