Javascript Saver fails with URL.createObjectURL(blob)

var optionssave = {
        success: function() {
            console.log("Yay! File saved to dropbox");
        },
        cancel: function() {
            console.log("Whoops file not saved!");
        },
        error: function(errorMessage) {
            console.log(errorMessage);
        }
    };

var blob = new Blob([setxml], {
            type: "text/plain;charset=utf-8"
});
var bloburlsav = URL.createObjectURL(blob);


Dropbox.save(bloburlsav, filename, optionssave);

Dropbox file chooser is working fine.

The dropbox file saver reaches to the point of displaying the file name and the save button, on clicking the save button, it displays, "Failed to load request" (screenshot attached)

You can visit the link live: https://tomatosmoothie.github.io/recipes/ and try it if you have the time.

Thanks.