Firefox 57 Unbranded does not allow legacy extensions

[Gingerbread Man]

Using an unbranded build of version 58, you can set extensions.legacy.enabled to true in about:config. This will enable legacy add-ons, but legacy APIs are constantly being removed, so your particular legacy add-ons may not function.

[morat]

Is this working for you anymore?

Dumby's hack broke in Fx 59.

A CB user got a few legacy extensions working in Fx 59 by taking the defaults\preferences\*.js files in *.xpi files and placing these *.js files into the folder with the channel-prefs.js file.

I got the Custom Buttons 0.0.5.8.9 fixed7pre and DOM Inspector Plus 2.0.17.1.2rc extensions working without Dumby's hack in Fx 58. I put the CB and DOMi Plus pref files into the folder with the channel-prefs.js file. I rather not use Dumby's hack in Fx 58 because it increases the startup time noticeably.

I set these preferences.

Code: Select all

// Disable Signing Requirement
// Enable Legacy Extensions
// Enable Non Multiprocess Compatible Extensions

pref("xpinstall.signatures.required", false);
pref("extensions.legacy.enabled", true);
pref("extensions.allow-non-mpc-extensions", true);

[therube]

Disabling e10s may affect what you might or might not get out of legacy extension...

[Gingerbread Man]

Custom Buttons 0.0.5.8.9 fixed7pre

Buttons that can't be added by webextensions can be added by userChrome.js scripts. No noticeable impact on startup time that I've seen.

[Frank Lion]

Disabling e10s may affect what you might or might not get out of legacy extension...

...and also - extensions.allow-non-mpc-extensions > true