It is possible that you use the autostop feature in the Turn Off the Lights Browser extension. This stops all those playing HTML5 videos and prevent the loading of this video player.
Solution Netflix Error Code: M7375
Try to reset the Turn Off the Lights settings.
1. Open the Turn Off the Lights Options page
2. Click on the Advanced Options tab
3. Scroll to the bottom of the web page, and click on the gray button “reset the Turn Off the Lights settings”.
4. And restart your web browser
You can also whitelist Netflix from the autostop feature, just by enabling the whitelist checkbox and type the Netflix domain in the selection box.