In case anyone still has to support legacy fancybox with jQuery 3.0+ here are some other changes you'll have to make:
.unbind() deprecated
Replace all instances of .unbind
with .off
.removeAttribute() is not a function
Change lines 580-581 to use jQuery's .removeAttr()
instead:
Old code:
580: content[0].style.removeAttribute('filter');
581: wrap[0].style.removeAttribute('filter');
New code:
580: content.removeAttr('filter');
581: wrap.removeAttr('filter');
This combined with the other patch mentioned above solved my compatibility issues.