Sorry This Photo Is Not Available For Your Collection

Hoping someone might be able to help with this as I need this to work in the next 12 hours. I have created some Bonus Coupons that are one time use. They result in the clients receiving 5 digital images for a hugely discounted rate. However, after I have added one photo to the coupon, it then won't let me add the other 4 and comes up with 'Sorry this photo is not available for your collection'. How can I make it so that clients can add 5 photos and get it for a specific discounted price - it is a public gallery so I need to use codes to ensure the right people are getting the discounts. 

Thank you.

If your collection has "Do not allow adding photos to this collection from different galleries or sub-galleries" checked and you are trying to add from different sub galleries it will do that.

Edit the collection and uncheck that option and see if that changes things.

That seems to have worked. I am assuming I cannot just limit it to one gallery then for clients. Ideally I would just like them to use photos from one event gallery. Many thanks.

You can create a new collection with the limit and a new price list (or copy) and use that in the events you do not want to offer buying from other galleries.