This means that there seems to be a technical issue with how the campaign was submitted, either:
The campaign does not have any items in it, or
The destination URL drives to a non-existent page or the wrong page
Example: A new campaign was successfully set up, but ads have not been added to it or after adding ads to the campaign they were deleted after the campaign was submitted for review.
Example: When the review team goes to the landing page, they see a ‘404 error’ message.
How To Fix This
Check that there are ads in the campaign (Creating a campaign does not mean that there is content in it to run. The content that you want to run must be added as campaign ads. When setting up a new campaign, make sure to add campaign ads to the campaign inventory before submitting it. Each campaign ad should have a title, thumbnail image or video creative, and destination URL)
Check that the destination URL and landing page are functioning properly and update the URL of the campaign ad
To learn more about setting up a new campaign setting, click here. To learn more about adding URL parameters and tracking, click here.
To learn how to fix and resubmit the campaign or campaign ad, click here.