I've removed your e-mail per forum policy as we won't email you with support. There's only forum support.

You can change that pref at about:config. Simply plug about:config into your Address Bar, hit enter, and click the button saying you'll be careful.

On the top, you'll find a search box / filter box. Start typing the pref above ( security.insecure_field_warning.contextual.enabled) and double click it to set it to false (it should be true and unbolded and bolded and false). Restart Firefox and the message should be gone.

I think you found that preference name in another thread, so let me provide a little more context for you and anyone else reading.

Firefox 52 provided a new warning on HTTP sites to remind you that your login is not protected from interception because there is no encryption on HTTP connections, your username and password are sent out over the network as plain text. See: Insecure connection password warning in Firefox.

The warning panel should appear below the user name and/or password field, but depending on the site's styling, it might block the field. In that case, you can clear it by tapping the Esc key or move to the next field by pressing the Tab key.

If that doesn't work or is too inconvenient:

To Remove the Warning Panels

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.

(2) In the search box above the list, type or paste insec and pause while the list is filtered

(3) Double-click the security.insecure_field_warning.contextual.enabled preference to switch the value from true to false

(4) Assume this login could be easily stolen and avoid re-using it on important sites