The Dataimport tab of a core will hang with a loading screen or display the previously accessed tab instead of showing the expected dataimport screen.
The console in Chrome has the following error log, but it's obvious to me that it's trying to run un-transpiled coffeescript:
naturalSort.js?_=6.0.0:30 Uncaught SyntaxError: Unexpected token ILLEGAL jquery.sammy.js?_=6.0.0:120 [Fri May 22 2015 23:36:59 GMT-0700 (MST)] runRoute get #/db/dataimport dataimport.js?_=6.0.0:48 Uncaught ReferenceError: naturalSort is not defined
The file in question can be viewed here: https://svn.apache.org/viewvc/lucene/dev/trunk/solr/webapp/web/js/lib/naturalSort.js?view=markup
I was able to verify this in my own build as well as the nightly builds hosted on the Apache Jenkins server with the default DIH example (bin/solr start -e dih).