Thanks for this, but I'm not so sure that this is the issue since it has been set like that for a very long time (git blame says 7 years...), long before Mozilla pulled the previously working version. Have you tested it for an extended period?

If it does indeed solve/workaround the issue, we need to investigate why that is, because it should work with "persistent": false.

These docs on migrating to event pages state:

Implementing non-persistent background scripts will greatly reduce the resource cost of your extension. Most extension functionality can be supported by an event based background script. Only under rare circumstances should an extension have a persistent background, as they constantly consume system resources and can cause a strain on lower-powered devices.

You wrote:

persistent: true is also the default behavior when unset. And I don't know of any extension that uses persistent: false.

These docs state:

The only occasion to keep a background script persistently active is if the extension uses chrome.webRequest API to block or modify network requests. The webRequest API is incompatible with non-persistent background pages. By default, "persistent" is set to true.

According to this, since we do not use the webRequest API, we should not need persistent background scripts (unlike ublockOrigin, ClearURLs, Cookie-AutoDelete, I presume).

I've scratched my head around this for quite some time now, and honestly... I don't know.

The two things that made it work are:

• persistent: true
• removing the static/installed.js file from the list of background scripts.

It doesn't make sense.

And yes, you're right, it only appears in recent versions of firefox.

removing the static/installed.js file from the list of background scripts.

Oh really? Could you give the changes in #110 a shot? It removes the need for installed.js.

#110 works perfectly

I think #110 should have resolved the issue. Thanks for digging this up though, good stuff!