User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:46.0) Gecko/20100101 Firefox/46.0 Build ID: 20160307004010 Steps to reproduce: * Clone https://github.com/davezuko/react-redux-starter-kit * Run the demo * Try to inspect some element styles · I've tried disabling e10s and starting with a fresh profile and the problem persists. · When turning on the browser console I can see this error: resource://devtools/server/actors/stylesheets.js:1186:0 A promise chain failed to handle a rejection. Did you forget to '.catch', or did you forget to 'return'? See https://developer.mozilla.org/Mozilla/JavaScript_code_modules/Promise.jsm/Promise Date: Tue Mar 08 2016 13:58:40 GMT-0600 (CST) Full Message: Component returned failure code: 0x804b000a (NS_ERROR_MALFORMED_URI) [nsIIOService.newURI] Full Stack: JS frame :: resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/actors/stylesheets.js :: dirname :: line 1186 JS frame :: resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/actors/stylesheets.js :: StyleSheetActor<._setSourceMapRoot :: line 790 JS frame :: resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/server/actors/stylesheets.js :: StyleSheetActor<._fetchSourceMap/</map< :: line 763 JS frame :: resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js :: Handler.prototype.process :: line 933 JS frame :: resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js :: this.PromiseWalker.walkerLoop :: line 812 Actual results: CSS Rules are not showing on DevTools CSS panel Expected results: CSS Rules should be visible and editable on the DevTools panel

Wait for the next update of Aurora, it'll be fixed.