A gentle correction gives someone a way to improve without having to disappear first.

Correction delivered harshly asks a person to absorb a judgement about themselves before they can absorb the information. Most people cannot do both at once, so they retreat, go quiet, or defend. A gentler version separates the error from the person and leaves them standing in the room with something they can use. The point is not softness for its own sake, it is that someone who feels able to stay is someone who can change.

When you next tell a person that something went wrong, say the specific thing and stop. Leave out the summary of their character.