As a manager, what are the most important reasons that make you nervous?

Thanks 

Neglect which have done by my employees 

1. Artificial "urgencies" created by attention seeking managers / peers

2. Attempting to Lead the company into a wrong direction by influential executives' vested interests

3. Lack of integrity in dealings.

Grouping in teams and non collaboration of departments.

Facing a Dissatisfied customer is really makes me a nervous, Most of the time that they will listen and able to buy some more time to complete the job.But some customers are never gonna listen our part and hard to convince them.

Thanks.

As Manager non collaboration makes you much nervous

The purposed errors and the non collaboration

As a manager being nervous,stressed sometimes is good to increase focus on task

I may get nervous when the task is near deadline, team is slowing down, or confusion is assimilated throughout the task needed to be executed