Not a constructor

Not a constructor

This used to work, but it has suddenly stopped. I used some jquery to make a smooth scroll when a link was clicked.

I'm getting this error in my console

jQuery.fx.ScrollTo is not a constructor
ScrollTo()myeffects.js (line 84)
e([div#headerbackground], function(), undefined)jquery.js (line 11)
e(function(), undefined)jquery.js (line 11)
ScrollTo(1000)myeffects.js (line 83)
(no name)()myeffects.js (line 18 )
e(Object type=click target=a.scroll currentTarget=a.scroll)jquery.js (line 11)
e()jquery.js (line 11)
[Break on this error] new jQuery.fx.ScrollTo(this, o);

My site is at epicalex.com - if you go to a post and scroll to the bottom, click on back to top you will see the problem