Script not accessible in FF 44

Our FF extension can’t import scripts dynamically in local page only in FF 44.
I just follow the guide from here ( https://developer.mozilla.org/en/docs/Web/API/HTMLScriptElement ) and write the below code.
It does work below FF 44 but always fail to execute in 44 with the error message “URIError: The script toolbarpx://nsc/locale/url_check.js is not accessible.”

// This initial code need to perform before other script.
(function(w,d,n) {
 // Only firefox need to load this javascript to replace the token
 if (n.indexOf("firefox") > -1 && /^tmpx:\/\//.test(window.location.href)) {
           w.addEventListener("load", function() {
    function loadError (oError) {
        throw new URIError("The script " + oError.target.src + " is not accessible.");
    }

             var script = d.createElement("script");
    script.type = "text\/javascript";
    script.onerror = loadError;
                    script.onload = function() {
                             init();
                             post_init();
                    };
                    d.body.onload = null;
                    d.body.parentNode.insertBefore(script, d.body);
    script.src = "url_block.js";
    script.crossorigin = "anonymous";
           }, false);
 }
}(window, document, navigator.userAgent.toLowerCase()));

I wonder if any big change has made in 44, but found nothing in release note.
I guess maybe FF 44 doesn’t allow to use script label with non http(s) source.
Could you guys please help on this issue?
Many many thanks in advance.

I think more context is needed here. Did you set up the custom “toolbarpx” protocol? Why do you need to use that, rather than “chrome” or “resource”?