Hi Ellie,
It looks like originally you created a Custom Field Type of “Promotions” (rather than Promotion) and then afterwards changed the Display Name. The API name of the CFT doesn’t update when you change the display name, but we’re checking explicitly that the field you create uses the promotion custom field type.
Could you recreate the Custom Field Type with the correct name (Promotion) and then recreate the custom field Restaurant Promotions, as you have it?