I have a WebExtensions add-on that is side-loaded by a Windows installer. This add-on has been used by thousands of customers for several years now. One of my customers informed me today that the add-on no longer works in Firefox 62.
Works in 61
Disabled in 62
I have been able to verify. The add-on works fine in 61, and is disabled in 62. It is signed by Mozilla, uses the WebExtensions API, and is listed on the AMO website as supporting FF versions 42.0 - *.
I have thoroughly read both the 62 release notes and the Extensions in Firefox 62 blog post. I don’t see anything that would explain why this extension would stop working. What am I missing?
Any help greatly appreciated. Thank you.
I think how signing works has been slightly updated and you may have to get a newly signed version for it to work in 62, not totally sure on that, just some chat I’ve heard on the street corner 
Thank you for your response. It sounds plausible, especially since I noticed the following message in the browser console:
addons.xpi-utils WARN Add-on AllworxInteractSyncForFirefox@allworx.com is not correctly signed.
To test the theory, I just signed the latest version of the extension:
Unfortunately, it exhibits the same behavior. It runs fine on version 61, but refuses to run on 62:
To follow up, the answer lies in this blog post:
https://blog.mozilla.org/addons/2018/02/22/removing-support-unpacked-extensions/
I missed this piece of information.
