Is the video available to you? Can you Watch the video?
- Go to the private video page on Facebook.com.
- Press CTRL + U button to view page source
OR
right click on the page fb private video, then click on the option "View page source code"
- On the page source tab, copy all the source code text. (Use CTRL + A to select all and then CTRL + C to copy).
- In the below text field paste all source text you have copied using CTRL + V
- Click on the "Download" button
Paste full text of 'view source' from Facebook video page here...