Hi all.
I confirm this error is Facebook internal error itself. It will not affect other javascript codes because seem everything is from inside Facebook iframe.
To display the page fans box without faces of fans, you must still check facepile=true
but use iframe instead of code from Facebook developing page.
Here is my example about facebook page fans iframe without error:
<iframe name="f12547a894" width="300px" height="1000px" frameborder="0"
allowtransparency="true" allowfullscreen="true" scrolling="no" title="fb:page Facebook Social Plugin" src="https://www.facebook.com/v2.4/plugins/page.php?
adapt_container_width=true&app_id=403849583055028&channel=http%3A%2F%2Fstatic.ak.facebook.com%2Fconnect%2Fxd_arbiter%2FxRlIuTsSMoE.js%3Fversion%3D41%23cb%3Df11c9c3f4%26domain%3Dmagonedemo.blogspot.com%26origin%3Dhttp%253A%252F%252Fmagonedemo.blogspot.com%252Ff289e16c38%26relation%3Dparent.parent&container_width=301&hide_cover=false&href=https%3A%2F%2Fwww.facebook.com%
2Fpages%2FSneeit%2F622691404530609&locale=en_GB&sdk=joey&show_facepile=true&show_posts=false&small_header=false&width=300" style="border: none; visibility:
visible; width: 300px; height: 130px;" class=""></iframe>