User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:55.0) Gecko/20100101 Firefox/55.0 Build ID: 20170613054006 Steps to reproduce: Open Network Monitor (Ctrl+Shift+E), make a request that returns a HTML response, click on the request and open the response tab. Actual results: The plain HTML markup was exhibited. Expected results: As the removal of the preview tab in bug 1350229, the preview of the HTML should be rendered in the response tab.

I get the same on version 57.0a1 (2017-08-07) (64-bit) Response is 200, type is html, header says text/html and in response i get the code instead of the preview.

I get the same 55.0.2 (32-bit) content-type text/html; charset=utf-8 Code is displayed, but no HTML rendered

This is not solved. I get this with v.57 and had it with 56 as well. I even tried with an all new profile to see if it would solve anything. It did not. /E

(In reply to Emil from comment #4) > This is not solved. I get this with v.57 and had it with 56 as well. > > I even tried with an all new profile to see if it would solve anything. It > did not. > > /E It's fixed in bug #1353319 for Firefox 59.