Firefox popup 'Authentication Required' when accessing Stack Overflow

Question

One of the more recent updates to Firefox started to popup a message whenever I access StackOverflow from my work machine, along the lines of:

'The proxy moz-proxy://xxx:8080 is requesting a user name and password. The site says: "moz-proxy://xxx:8080"

The message consistently pops up 6 times, I can cancel all of them and the page looks fine. If I change to another SO page I get the same issue.

This is not a problem in Explorer and I haven't found any other website that gives me this problem - it's most irritating because SO is my first port of call for tech issues! I've had a hunt round the web and there are a couple of config suggestions (network.proxy.share_proxy_settings=false and network.automatic-ntlm-auth.allow-proxies=false) that I have set but they make no difference. I am out of my depth here!

Any ideas?

Answer 1

Solved from the comment left by e19293001 which pointed to this: Firefox asks for proxy details, but only when accessing facebook

Go to the URL about:config, search for the key network.websocket.enabled and switch it to false.

Now able to access SO without those annoying popups!

Answer 2

I put a new add-on on my Firefox and gave it auto-update permission and the next time I opened Mozilla Version57 I got the proxy "babble" and the same thing by closing and re-opening.

Simply open your add-ons and either disable all auto updates, or disable the auto update that is most recent like I did, or do them one at a time as a process of elimination.

Once you reverse the auto update causing the issue the problem is gone for good. In my case it was "setupVPN" add-on.