[Firefox] Cannot manually install/update (add-on not signed)

[BillyJoeJimBob]

Thank you for you assistance on this! The old AMO v2.54 and current v2.55 userscript both function as expected. In a probably apples to oranges comparison, I was somehow able to install another extension Bypass Paywalls Clean that was removed from addons.mozilla.org earlier this year using about:addons > Install Add-on from file to install an .xpi file. see: https://gitlab.com/magnolia1234/bypass-paywalls-firefox-clean/-/releases. I've been using that unsigned extension in Firefox stable for a few months and It even self updates but I assume there is some security risk there.

         Previous information I gave was inaccurate,  because I was used to testing the development builds through `about:addons` > `Manage Your Extensions` > `Debug Add-ons`.

Unfortunately, you will need to use an unbranded build, development build or another browser based on Firefox (Pale Moon, Waterfox, etc.) to install unsigned extensions.

We can not do anything about this issue, since our add-on got removed from addons.mozilla.org and therefore we are also unable to sign the add-on for self distribution.

I will make sure to update the README soon to reflect that we don't support Firefox Stable anymore.

Originally posted by @drunkwinter in #188 (comment)

[drunkwinter]

No need to open a new issue, #188 is still open for comments.