Unfortunately, yesterday's otherwise fantastic 1.7.17 release had a packaging snag that broke many installs. It's one we've seen before, and was due to a third-party tool we were using for building our JavaScript bundles, which has had a couple broken releases.
The new 1.7.18 release switches to using UglifyJS for JavaScript minification. This build should restore your installs to perfect working order.
Release notes are available.