This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Websockets on localhost stopped working in 66.0

  • 6 replies
  • 1 has this problem
  • 1 view
  • Last reply by Istoman

more options

After updating to Firefox 66.0 on MacOS 10.13.6 today, websockets on my localhost stopped working.

When using Create React App (version of "react-scripts": "2.1.8" => "webpack-dev-server": "3.1.14" => "sockjs": "0.3.19"), hot reload is broken and I get following error in the console:

`The connection to ws://localhost:3000/sockjs-node/743/khw0phgj/websocket was interrupted while the page was loading.`

When I tried https://www.websocket.org/echo.html, it works fine and no problems with hot reload in Chrome 72.0.

How can I debug and fix this problem please? (when I googled the error message, I got a lot of outdated advice from previous versions of Firefox)

After updating to Firefox 66.0 on MacOS 10.13.6 today, websockets on my localhost stopped working. When using Create React App (version of "react-scripts": "2.1.8" => "webpack-dev-server": "3.1.14" => "sockjs": "0.3.19"), hot reload is broken and I get following error in the console: `The connection to ws://localhost:3000/sockjs-node/743/khw0phgj/websocket was interrupted while the page was loading.` When I tried https://www.websocket.org/echo.html, it works fine and no problems with hot reload in Chrome 72.0. How can I debug and fix this problem please? (when I googled the error message, I got a lot of outdated advice from previous versions of Firefox)

Modified by Peter Hozák

Chosen solution

No error in 65.0.2 when I downgraded => most likely a bug in Firefox, reported as https://bugzilla.mozilla.org/show_bug.cgi?id=1536843

Read this answer in context 👍 0

All Replies (6)

more options

Click the link using Windows 10 and it came up with no progblems and it said also "This Browser Supports WebSocket". So what is the error screenshot saying?

more options

Chosen Solution

No error in 65.0.2 when I downgraded => most likely a bug in Firefox, reported as https://bugzilla.mozilla.org/show_bug.cgi?id=1536843

Modified by Peter Hozák

more options

WestEnd said

So what is the error screenshot saying?

The error message was in my original post - repeating here if it was hard to notice:


The connection to ws://localhost:3000/sockjs-node/743/khw0phgj/websocket was interrupted while the page was loading.

more options

Does toggling this pref on the about:config page make a difference?

  • network.websocket.allowInsecureFromHTTPS
more options

cor-el said

Does toggling this pref on the about:config page make a difference?
  • network.websocket.allowInsecureFromHTTPS

nope

more options

I can second this is happening only since 66.0 and also on a Vue dev server (so this is not a react-scripts thing).