This error code indicates that at least one child event associated with this blueprint already has a discount with the same code. You will want to remove/rename the existing discount code in the child event(s) or use a different discount code in the blueprint before attempting to push the changes to your child events again.

If you are having issues locating the specific child event(s) with the discount code, please contact support referencing this article (105546) and provide the discount code from the error message.