This one error means that premier, live stream, and embedded restricted videos cannot be promoted via this service.
How to check embedding settings:
Go to YouTube studio and select a video you would like to promote
Go to "Details" and choose “Show More"
Tick the box “Allow embedding”
How to check age restrictions:
Go to YouTube Studio and select a video you would like to promote
Go to "Details" and choose “Age restriction (advanced)”
Tick “No, don't restrict my video to viewers over 18 only” option
Now you can order Video Promotion.
If the problem remains unsolved, please check that you saved all settings for the correct video and contact our support team via live-chat on viewsta.com