The worst experience as a leader in my life

Think about a time when you experienced failure as a leader in your organizational life such as (ADNOC) when you were less effective than you should have been while managing yourself and/or other people. Examples might include failure to secure an important client, stalled promotion, frustrating project management or team management experience, inability to manage upwards, difficult colleague or subordinate, etc.
Briefly describe the situation and analyze the contributing factors that made you less than effective.
What is important is the thoughtful analysis of what caused you to be ineffective in that leadership situation? Suggest alternative courses of action given the learning from the course

Questions shall be answers as follow:
1.Failure is well-defined and meaningful?
2.Contributing factors can be linked to the failure?
3.After reflection, what caused you to be ineffective as a leader?
4.What alternative courses of action could you take to prevent the failure from happening in the future