blockUI requires jQuery v1.3 or later! You are using v1.11.1

From semantic-mediawiki.org

OK, will do. Thanks! I was blindly following the instructions here which say 1.9.*. Am I missing something or do those instructions need updating?

17:35, 11 March 2015

Well, there is always room for improvement I believe. The following diff should help the cause.

18:37, 11 March 2015