When creating new campaigns, they are reviewed by Amazon to check if they are aligned with their creative guidelines. If the campaign does not meet the guidelines, it will be rejected. Rejected campaigns are displayed in the Ad Optimizer with the status "Error".
The campaign can be re-submitted, but then a new campaign will be created.
Our best practice is to adjust the creative in Amazon Console.
Open the campaign in the Amazon Console and click on the Ad group.
Now the creative can be edited.
The version of the creative that has not been approved is displayed.
The creative can be edited.
Open the headline tab. The headline can now be edited.