in the Browser console we have
:TypeError: listener.off is not a function Stack trace: Tab<.attach/listener@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/tabs/tab-firefox.js:218:9 emitOnObject@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/event/core.js:112:9 emit@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/event/core.js:89:38 EventParent<.attachItem@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/remote/utils.js:27:5 setFrameProcess@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/remote/parent.js:157:3 frameAttached@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/remote/parent.js:298:5 core.js:106
in the Browser console we have
:TypeError: listener.off is not a function Stack trace: Tab<.attach/listener@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/tabs/tab-firefox.js:218:9 emitOnObject@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/event/core.js:112:9 emit@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/event/core.js:89:38 EventParent<.attachItem@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/remote/utils.js:27:5 setFrameProcess@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/remote/parent.js:157:3 frameAttached@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/remote/parent.js:298:5 core.js:106
I have opened a bug with mozilla: https://bugzilla.mozilla.org/show_bug.cgi?id=1246370