Collapsiblock disables dhtml and AJAX on 4.7.1

I had collapsiblock working on three different sites. Since upgrading to 4.7.1, it has stopped working (except for the very first block on one of the sites).

What's more, it has disabled the dhtml on admin/settings, leaving the page sections closed (unavailable), and (I believe) the AJAX freetagging when creating a new post.

Disabling collapsiblock has rectified the problem, so it seems to be just this one module of the jstools package.