A scaffold or scaffolding in a dream usually indicates that there is some kind of temporary structure in our lives.
If we are building something new, the scaffolding will support us while we build, whereas if we are repairing the old it will support the previous structure while we make the necessary changes.
A hangman’s scaffold will suggest that a part of our lives must come to an end. We may, for instance, be aware that we have offended against some of society’s laws and beliefs, and must be held to account. We also may need to look at our propensity to be a victim.