UI broken with nw.js 0.42.6

I tried running Purr Data with the latest version of nw.js (0.42.6). There is a problem that seems to prevent window elements from being created. For example, the preferences dialog and patch windows are simply blank:

Purr Data with nw.js version 0.42.3 doesn't have this issue.

I don't see any useful errors logged in the console.