Thread:Project:Current issues/All JavaScript broken in Opera due to jQuery not loaded?/reply (5)

The absence of the type-attribute is unlikely a problem. One of the reasons it was safely removed in HTML5 is because older browsers (even those without special HTML5 support) already defaulted to 'text/javascript').

If you think it is the problem though, feel free to check out MediaWiki and see if it works if you re-add that attribute in a local patch.