Bugzilla

Hooray, glad to hear it!

Not so glad to hear that that's the underlying issue, though. That means this is a website bug, essentially; the sites are doing different things depending on whether or not they think you're using Firefox, and they're testing for the presence of this ancient Firefox-specific `InstallTrigger` API as a way of checking which browser you're using.  And unfortunately, their Firefox-specific codepath is broken (but things go just fine if we take the other codepath).

If you haven't already, could you list the sites where you've confirmed that (a) the problem exists and (b) this pref-flip fixes the problem?  In some cases we might be able to reach out and get the sites to fix their bug (just removing the broken Firefox-specific codepath), but I want to be sure we're reaching out to the right sites.

Hooray, glad to hear it!

Not so glad to hear that that's the underlying issue, though. That means this is a website bug, essentially; the sites are doing different things depending on whether or not they think you're using Firefox, and they're testing for the presence of this ancient Firefox-specific `InstallTrigger` API as a way of checking which browser you're using.  And unfortunately, their Firefox-specific codepath triggers this breakage; but things go just fine if we take their other codepath, the codepath that other browsers get.

If you haven't already, could you list the sites where you've confirmed that (a) the problem exists and (b) this pref-flip fixes the problem?  In some cases we might be able to reach out and get the sites to fix their bug (just removing the broken Firefox-specific codepath), but I want to be sure we're reaching out to the right sites.

Hooray, glad to hear it!

Not so glad to hear that that's the underlying issue, though. That means this is a website bug, essentially; the sites are doing different things depending on whether or not they think you're using Firefox, and they're testing for the presence of this ancient Firefox-specific `InstallTrigger` API as a way of checking which browser you're using.  And unfortunately, their Firefox-specific codepath triggers this breakage; but things go just fine if we take their other codepath, the codepath that other browsers get.

Could you list the sites where you've confirmed that (a) the problem exists and (b) this pref-flip fixes the problem?  In some cases we might be able to reach out and get the sites to fix their bug (just removing the broken Firefox-specific codepath), but I want to be sure we're reaching out to the right sites.  (You mentioned "stallionexpress.ca, eBay.ca, Etsy.com, etc." in comment 0 -- it'd be great if you could confirm the problem and the fix for all three of those sites, and if you could let us know if there are any other sites hiding in your "etc." there. :))