In conversation

Where it shows.

Acknowledge first

When someone is upset, acknowledgement has to come before solutions or the solution reads as dismissal. That sounds hard: what is the part that concerns you most?

Advice arrives better when asked for.
Do not argue someone out of a feeling; address the situation instead.

Conflict

Describe the behaviour and its effect rather than the person's motives. You can observe what happened; you cannot observe why they did it.