There are some changes coming to Firefox that might impact enterprise users, so i wanted to make folks aware of them.

Firefox 42 has a change to the permission manager so that permissions are based on the origin not just the host. This means that code like this in your AutoConfig file:

Services.perms.add(NetUtil.newURI("http://" + hostname), ...

will only apply to http. You need to be explicit with both:

Services.perms.add(NetUtil.newURI("http://" + hostname), ...
Services.perms.add(NetUtil.newURI("https://" + hostname), ...

Existing permissions will be migrated to both http and https. I've updated the CCK2 to account for this, but you'll need to rebuild your distribution.

Firefox 44 has some major changes coming to JavaScript let/const behavior that could impact your AutoConfig file. I'll be making sure the CCK2 is compatible, but you should make sure you're testing with the latest Firefox 44. Obviously this will impact the Firefox 45 ESR as well, so you'll want to do lots of testing there.

Finally, I got a question about the Firefox/Windows 10 page appearing even when you have upgrade pages turned off. Unfortunately this page bypasses the existing upgrade code. To make sure it doesn't appear, set the preference browser.usedOnWindows10 to true.

https://mike.kaply.com/2015/10/15/windows-10-permission-manager-and-more/