i got same problem..i have default-bootstrap theme and my version is 1.6.0.9 and after updating some module i got this error..
also social icons not show up anymore
on global.css i found this
.footer-container #footer #social_block ul li.facebook a:before { content: "\f09a"; } .footer-container #footer #social_block ul li.twitter a:before { content: "\f099"; } .footer-container #footer #social_block ul li.rss a:before { content: "\f09e"; } .footer-container #footer #social_block ul li.youtube a:before { content: "\f167"; } .footer-container #footer #social_block ul li.google-plus a:before { content: "\f0d5"; } .footer-container #footer #social_block ul li.pinterest a:before {