[Plugin: FancyBox for WordPress] jQuery("a.fancybox").fancybox is not a function

I keep getting this error:

jQuery("a.fancybox").fancybox is not a function

The blog is https://camilla-s.com – I’ve tried the troubleshooting steps, and including

<script type='text/javascript' src='https://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js'></script>

<script type='text/javascript'>try{jQuery.noConflict();}catch(e){};</script>

As you do on your blog – doesn’t really help. I haven’t got any other gallery plugins loaded.

Any ideas?

https://www.ads-software.com/extend/plugins/fancybox-for-wordpress/