Basic script breaking Ugoiras?

I use this script to quickly view an image and still be able to click back:

if (history.length === 1) {
    location.assign($("#image").eq(0).attr("src"));
}

Ugoiras display an error which I just click back to view, but the post page doesn't load because of this script, even though it's not doing anything.

Ugoira don't have have src attribute.

Should it matter? The script shouldn't even work once I click back.

I don't know what problem you're having but the first step would be to fix the bug in your script. Only set the location to src if src !== undefined.