UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:57.0) Gecko/20100101 Firefox/57.0

Example URL:
twitter.com, theguardian.com

Steps to reproduce the problem:
1. navigate to a url 
2. after the page is loaded the user sees a blank page
3. 

What is the expected behavior?
The page should be visible

What went wrong?
The behaviour is erratic. The same url can be shown correctly some times and others not. It seems linked to an extremely long css stylesheet that sometimes is injected on the page.
You can see the beginning of the stylesheet in the pictures in attachment.

Does it occur on multiple sites: Yes

Is it a problem with a plugin? Yes ADBLOCK PLUS

Did this work before? N/A 

Does this work in other browsers? N/A

Chrome version: <Copy from: 'about:version'>  Channel: canary
OS Version: OS X 10.13
Flash Version: Shockwave Flash 28.0 r0

No
 

Deleted: Screen Shot 2018-01-23 at 8.30.55 AM.png 1.7 MB

	Screen Shot 2018-01-23 at 8.30.55 AM.png 1.7 MB View Download

Deleted: Screen Shot 2018-01-23 at 8.29.41 AM.png 1.4 MB

	Screen Shot 2018-01-23 at 8.29.41 AM.png 1.4 MB View Download