When publishing your ads to Facebook there can be a number of reasons why they failed to publish. After publishing your ads you'll be able to see the status in the 'Publish queue'.
If you scroll to the right hand side of this section you'll be able to see the reason why the ads failed to publish.
If there's no error message we would suggest attempting to publish fewer ads simultaneously (< 150).
Please note that if your ads get stuck in the publishing queue for any reason you'll need to clear the queue and republish your ads after addressing the issue.