"browser_specific_settings": {
   "gecko": {
     "id": "fasty@a_domain.com",
     "update_url": "https://a_domain.com/appextension/updates.json"
   }
 },

This is a self-hosted extension, that initially seemed to be updating. Using File > Open, the current installed version is 1.8.61 In the approved extension's (1.8.61) manifest: "browser_specific_settings": { "gecko": { "id": "fasty@a_domain.com", "update_url": "https://a_domain.com/appextension/updates.json" } }, After tapping Check For Updates, I can see the following in Browser Console: 11:28:34.044 XHR GET https://a_domain.com/appextension/updates.json [HTTP/2 200 OK 254ms] 11:28:34.201 1651073314201 addons.update-checker DEBUG Found an update entry for fasty@a_domain.com version 1.8.61 11:28:34.201 1651073314201 addons.update-checker DEBUG Found an update entry for fasty@a_domain.com version 1.8.7 Here is where the issue gets interesting. Having downloaded all the xpi files, supposedly signed, today while attempting to manually install a newer version, Firefox oftentimes complains "This add-on could not be installed because it has not been verified." The Console reports: 12:06:36.478 1651075596478 addons.xpi WARN Download of https://a_domain.com/appextension/fasty-1.8.7-fx.xpi failed: signature is required but missing According to the Developer Hub, the resulting xpi has been signed. I don't know what to try to get automatic updates to work. Please suggest. David