I released a new version of a firefox webextension, Copy All Tabs last night. The code is open source and available on github.
The new version fixes many bugs and is overall more stable. It works as expected on Windows and Mac (Firefox 61).
However, when I was testing on Linux (both Firefox 60 and 61), the "Copy Tabs" function fails.
Component returned failure code: 0x80040111 (NS_ERROR_NOT_AVAILABLE)
The function that fails on Linux is located in this file: https://github.com/charlesbrandt/copy_all_tabs/blob/master/ff-web_extension/background.js
The major shift was moving the copy and paste functions from a content script that was injected into the active tab's page to the background.js file. The content script approach was failing for Firefox specific pages (e.g. about:debugging) for security reasons.
Given the discrepancy, I'm inclined to think it has something to do with Firefox, but if it's a problem in the webextension I'd be happy to fix it.
If this is a bug in firefox, what is the best way to report it?
Alternatively, does anyone have a suggestion for how modify the extension so that it works effectively on all platforms?
Update: I followed @Dexter's advice and filed a bug in Bugzilla:
https://bugzilla.mozilla.org/show_bug.cgi?id=1473780
Since that time, the plugin eventually started working in newer versions of the browser.