A reason is required

Cancellations, voids, comps, overrides and moves all need one, and it comes from a list.

The action needs a reason and none was picked. The reason is not free text — it comes from your hotel's own list, so the reports can group by it.

• If the right reason is not offered, an administrator adds it in Lists & reasons. Picking the nearest wrong one is worse than the delay: it is what makes a reason report confidently untrue.
• "There is no list called ..." means the list itself is missing, which is a setup problem — see Lists and reasons.
• Some entries are manager only and are not offered to everyone.

Every reason lands on a report somebody reads: cancellations, voids, comps, rate overrides, room moves, out-of-order rooms.