Thanks for the report. I've updated CVS HEAD and the oacs-5-9 branch and bumped the version numbers, such that users of APM can get these changes smoothly.
The general recommendation is to consider the phase out of YUI in OpenACS applications since the development of YUI has stopped (in 2014, [1,2]).
[1] https://yahooeng.tumblr.com/post/96098168666/important-announcement-regarding-yui
[2] https://www.sitepoint.com/death-yui-can-teach-developers/
