What are the main causes of failure in professional life?

Lack of vision where you want to be in the next 5-10 years. 

Looking at the immediate benifit and not long term career. 

Being a coward. not taking the leap at the correct time. 

one fine morning you find that your career had gone flat for the last 5 years. 

Thanks for invitation,

In my opinion, the main causes of failure in professional life are:

1- Losing the right trace due to losing vision and strategic objectives.

2- Losing self- confidence.

3- Losing motivations for improvment and development.

4- Losing ambition and inspiration.

5- Very easy depressed and annoyed by others.

Lack of vision and planning........

• Lack of qualification 
• Lack of experience
• Lack of professionalism or soft skills 
• Lack of health
• Lack of interest

Thanks 

I support Dr. Abid's answer 

Not trying to strike a balance between the personal and professional life. There are few other personal reasons might influence the careers beside all other professional qualifications.

Basically, be yourself. Do what you can and try to do the best always. 

Upto my knowledge the main causes of failure in Professional life are

• Undefined objectives
• Lack of proper knowledge
• Lack of Professionalism
• Lack of determination
• Lack of getting bold decisions/ No risk management skills
• Improper utilization of time
• Have few or no linkages with other professionals.
• Fear of loss or failure