Word of caution: Do this at your own risk. Firefox has this feature for a reason <web safety>

Below are the steps to disable Firefox insecure password warnings:

-> Open a new tab, paste about:config into the address bar and hit enter -> If you see the “This Might Void Your Warranty” page, click the blue “I accept the risk!” button. This is shown to warn the user that these are advanced settings and should only be changed with proper knowledge and understanding -> In the Search box at the top, paste, security.insecure_field_warning.contextual.enabled -> Double click the setting to change it to “false”, this disables Firefox’s insecure password warning

Hope this helps!

Note that this message is meant as a warning that you could be vulnerable and that it shouldn't prevent (block) you from accessing the website.

You can press the ESC key to close a doorhanger with a warning message in the name and password field.

See also:

• https://support.mozilla.org/en-US/kb/how-do-i-tell-if-my-connection-is-secure
• https://support.mozilla.org/en-US/kb/insecure-password-warning-firefox

More:

• https://blog.mozilla.org/tanvi/2016/01/28/no-more-passwords-over-http-please/
• https://blog.mozilla.org/security/2017/01/20/communicating-the-dangers-of-non-secure-http/

I don't want to turn this feature off entirely. Incredibly the only time I ever see it lately is when I log into my new modem which has the address:

http://10.1.1.1/

The very few sites - among the thousands I visit - which require a log-in are all https sites.

It is a real annoyance, it needs a "whitelist" facility rather than an "all or nothing" approach.

Thanks in advance.