User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:41.0) Gecko/20100101 Firefox/41.0 Build ID: 20150929144111 Steps to reproduce: Open the developer tools and select the Style editor Actual results: With OS X El Capitan, sometimes the styles are not loaded and the tool goes in infinite loop. Expected results: The stylesheets should be loaded

Can you provide a URL that fails for you?

Inspector bug triage (filter on CLIMBING SHOES).

I have the same problem also using Windows 8.1 The inspector fails on that URL: http://skinlab.forumfree.it/ (but it's only an example ... it fails also on the Wishlist of Amazon).

Could this be a duplicate of Bug 1224558? From time to time, the "loading" spinner never disappears and the list of stylesheets is not loaded. Symptoms look similar.

I am experiencing this same issue with SharePoint 2013 Publishing sites that contain lists or libraries. Here is a page on our site that shows the problem: http://info2.scdot.org/StormReports/Pages/default.aspx This type of web part generates iframes. This is a similar page but with a different web part that does not generate iframes, so it works: http://info2.scdot.org/ED/Pages/engineering_directives.aspx. I am going to add this comment to bug 1224558 also.

Clearing the NI.

This will be fixed in bug 1224558.