BUG: extension removes sidebars

[7adidaz]

if the extension is active while using websites like this, it removes the sidebars
before

after

another example

[xpmn]

Hi, I know about this issue, this is problem of the rendering engine itself, I can't fix it. This extension doesn't do any changes on the page it's just apply filter on body tag and that's all.
You can read about this bug on bugzilla:
https://bugzilla.mozilla.org/show_bug.cgi?id=1106895