If you've updated firefox to the version 51 or newer, you surely noticed the annoying "This connection is not secure. Logins entered here could be compromised." into every http site user details.

It is a new policy they started so, in their opinion, to make everyone "finally" switch to https, obviously that's not going to happen anytime soon and is a killer for the thousands of users that everyday just want to login into their favorite sites and keep getting that damn popup window, other than not having their credentials pre-compiled as they open the login form.

Well, here's how to fix it:

1 - Go in the URL bar and type about:config, press enter
2 - Press on the blue "I accept the risk!" button
3 - Type "insec" on the top search bar of the config panel
4 - Select insecure_field_warning.contextual.enable
5 - Double click on it, it'll turn to "false"

Now you removed the annoying warning popup.

If you want to restore the pre-compiled credentials, you will also have to do these steps:

6 - Type "autofill" on the top search bar of the config panel
7 - Select signon-autofillForms.http, make sure you select the one that ends with .http
8 - Double click on it, it'll turn into "true"

Now you also fixed the pre-compilation of your login credentials.

Have fun!

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