I had noticed the same error. I have followed the suggestion and commented out those two lines. Seems to be functioning ok - I will let you know if I notice anything strange.
If you open the .js file, you will see several commented out lines where the developers are explaining what each part is for. Those lines all start with //. If you put those two slash marks on the lines mentioned, that effectively disables the alert box. I do not see that the alert box is really necessary so hopefully it will not affect anything else.