Websocket connection failing from Firefox extension - firefox

Question

I have a Firefox extension which connects to a websocket server and sends a message. I packaged it with web-ext build, renamed the .zip to a .xpi. Last month I installed it in Firefox after setting xpinstall.signatures.required to false in about:config. I added the SSL key to the Firefox certificate manager. It worked for a month. Yesterday there was probably a Firefox update and now the extension is blocked becaue it is not signed. After some research, I found that the regular Firefox has not allowed unsigned extensions for a long time. It makes me wonder what version I had until yesterday; I am working on a Ubuntu 20.04 system I set up 2 months ago.
When the extension is loaded manually with about:debugging, the extension works as it did before (websocket creation is successful and a message is sent).
I read online that Firefox Developer edition allows unsigned extensions. But after following the exact same steps, I cannot get the extension to work with a .xpi or by temporarily loading the extension. It is the same error in both circumstances:
Firefox can’t establish a connection to the server at wss://localhost:9501/.
The extension has a manifest and a background script
manifest.json:
{
"description": "weblogging app",
"manifest_version": 2,
"name": "weblogger",
"version": "1.0",
"browser_specific_settings": {
"gecko": {
"id": "browser_logger#example.org",
"strict_min_version": "50.0"
}
},
"background": {
"scripts": ["background.js"]
},
"permissions": []
}
background.js:
var websocketArguments = 'wss://localhost:9501';
var connected = new Boolean(false);
var webSocket;
createWebsocket();
function onError(error)
{
console.log(`Error: ${error}`);
}
function createWebsocket()
{
webSocket = new WebSocket(websocketArguments);
webSocket.onerror = onWebSocketError;
webSocket.onopen = onWebSocketOpen;
}
function onWebSocketError(event)
{
console.log("WebSocket error observed:", event);
};
function onWebSocketOpen(event)
{
console.log("WebSocket open: ", webSocket.readyState);
webSocket.send("hello there");
connected = true;
};

Answer 1

Whatever the reason I could not get the extension to work when unsigned, it was just easier to get it signed.
https://addons.mozilla.org/en-CA/developers/