Проблема с аддоном PlayX

Суть вот в чём. Когда запускаю видео, на экране начинает мерцать и моргать изображение. Видео при этом не хочет воспроизводиться, а консоль выдаёт вот такие блоки:

[HTML] Uncaught TypeError: Cannot read property 'PlayerState' of null
[HTML] Uncaught TypeError: Cannot read property 'PlayerState' of null
[HTML] Unable to post message to http://www.youtube.com. Recipient has origin https://www.youtube.com.

[HTML] Unable to post message to http://www.youtube.com. Recipient has origin https://www.youtube.com.

[HTML] Unable to post message to http://www.youtube.com. Recipient has origin https://www.youtube.com.

[HTML] Unable to post message to http://www.youtube.com. Recipient has origin https://www.youtube.com.

[HTML] Unable to post message to http://www.youtube.com. Recipient has origin https://www.youtube.com.

[HTML] Unable to post message to http://www.youtube.com. Recipient has origin https://www.youtube.com.

[HTML] Unable to post message to http://www.youtube.com. Recipient has origin https://www.youtube.com.

[HTML] Unable to post message to http://www.youtube.com. Recipient has origin https://www.youtube.com.

[HTML] Unable to post message to http://www.youtube.com. Recipient has origin https://www.youtube.com.

PlayX: Page loaded, preparing to inject

Как решить такую проблему?