Video is unavailable if clicking the "Open in new tab" link after sending a featured video from a channel or user

[SoftVision-CarmenFat]

[Affected versions]:

• Firefox 58.0 and up
• Min-Vid Shield Study Onboarding 0.4.7 - Shield Study
• Min Vid v.0.4.8 from Test Pilot

[Affected Platforms]:

• All Windows
• All Mac
• All Linux

[Prerequisites]:

• Latest Min-Vid Shield Study (Onboarding 0.4.7) was previously installed on a clean profile.

[Steps to reproduce]:

1. Open the browser with the profile from prerequisites and navigate to www.youtube.com
2. Click on a user/channel from the homepage (e.g. https://www.youtube.com/user/TheFrasernash).
3. Click on the "Play Now" button from the overlay displayed on the featured video.
4. Click on the "Open in new tab" link from the error view layout.
5. Observe what happens next.

[Expected result]:

• The video is opened and played in a new tab.

[Actual result]:

• The video is opened in a new tab, but "This video is unavailable" text message is displayed.

[Notes]:

• This is also reproducible on the Test Pilot version.

• This is only reproducible with the featured video of the channel/user.

• Here is a screenshot of the browser console when clicking the "Open in new tab" link:
  

• Attached a screencast of the issue: