maintainer-feedback requested: [Bug 216541] www/firefox: shows empty space on 'Data Choices' tab on about:preferences#advanced page

[bugzilla-noreply at freebsd.org]

John Smith <godevilove at ya.ru> has reassigned Bugzilla Automation
<bugzilla at FreeBSD.org>'s request for maintainer-feedback to gecko at FreeBSD.org:
Bug 216541: www/firefox: shows empty space on 'Data Choices' tab on
about:preferences#advanced page
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=216541



--- Description ---
It looks like this: https://imgur.com/D6eNou4l.png
And is 100% reproducible for me, even on a clean profile and on different
versions of Firefox (50, 51, compiled from ports, installed as a pkg).

On about:preferences (and about:addons) pages I am getting such a message in
the Error Console:

SDK worker-child started as frozen on unexpected initial document.readyState
Object { initialDocumentReadyState: "uninitialized", windowLocation:
"about:preferences" }  worker-child.js:62 [
view-source:resource://gre/modules/commonjs/sdk/content/worker-child.js ]