UserAgent: Mozilla/5.0 (X11; Linux i686; rv:45.0) Gecko/20100101 Firefox/45.0

Steps to reproduce the problem:
1. 
2. 
3. 

What is the expected behavior?
<script>alert('1');</script>

What went wrong?
<script>alert('1');</script>

Did this work before? N/A 

Chrome version: <Copy from: 'about:version'>  Channel: stable
OS Version: <script>alert('1');</script>
Flash Version: Shockwave Flash 11.2 r202

<script>alert('1');</script>