As a vendor, why does an event pickup code fail to scan?

Each pickup code is tied to one reservation, one vendor and one pickup date. If the scanner says the code was only valid on its pickup date, the reservation is for a different day: check the pickup date shown and ask the customer to come back on that date. If it says the reservation cannot be collected before its booked time, the customer is early: hand over from the start of their pickup window. If it says the reservation has already been collected, it was scanned before, so do not hand the items over again. If it says the reservation has not been paid, the customer's payment did not go through. If it says the pickup belongs to another vendor, the customer is at the wrong stall. If it says the code is invalid, ask the customer to reopen the code from their order or paste it manually. If the problem continues, contact support through the chat.