The person nobody invited
The robot cell is half installed when the operators' union representative hears that “automation means layoffs”. Nobody had invited the union to any meeting. Now the representative threatens to oppose the start-up.
Management says no jobs will be lost; operators will be retrained. But nobody told the people affected, and the rumour spread faster than the facts.
Stakeholders you forget do not disappear. They appear later, when they are hardest to manage.