console error MS Edge with ?features=web-components,scroll-behavior

[hades200082]

Unable to get property 'a' of undefined or null reference

Also, the scroll-behaviour polyfill doesn't seem to be applied

[wessberg]

Hey there. Thanks for reporting this issue. Can you provide me with more details? Which Edge version? And the error you are seeing, can you provide a stack trace?

[hades200082]

It's Microsoft Edge 42.17134.1.0

SCRIPT5007: SCRIPT5007: Unable to get property 'a' of undefined or null reference polyfill (1,31515)

In the code-block below the line that the error appears to be on is if (this.a.a.get(a))

    E.prototype.l = function (a, b) {
        var d = this;
        if (!(b instanceof Function))
            throw new TypeError("Custom element constructors must be functions.");
        if (!g(a))
            throw new SyntaxError("The element name '" + a + "' is not valid.");
        if (this.a.a.get(a))
            throw Error("A custom element with name '" + a + "' has already been defined.");
        if (this.c)
            throw Error("A custom element is already being defined.");
        this.c = !0;
        try {
            var c = function (b) {
                var a = e[b];
                if (void 0 !== a && !(a instanceof Function))
                    throw Error("The '" + b + "' callback must be a function.");
                return a;
            }, e = b.prototype;
            if (!(e instanceof Object))
                throw new TypeError("The custom element constructor's prototype is not an object.");
            var f = c("connectedCallback");
            var t = c("disconnectedCallback");
            var k = c("adoptedCallback");
            var h = c("attributeChangedCallback");
            var m = b.observedAttributes || [];
        }
        catch (q) {
            return;
        }
        finally {
            this.c = !1;
        }
        b = { localName: a, constructorFunction: b, connectedCallback: f, disconnectedCallback: t, adoptedCallback: k, attributeChangedCallback: h, observedAttributes: m, constructionStack: [] };
        ba(this.a, a, b);
        this.g.push(b);
        this.b || (this.b = !0, this.f(function () {
            return fa(d);
        }));
    };

[wessberg]

Can you provide me with a repro? I'd like to understand what you are calling customElements.define with since that seems to be triggering the error.

[wessberg]

Hey there. Since I haven't received any updates from you on this issue for many months, I'm closing the issue. Feel free to open it again if the issue still persists.