In your opinion, what are the most important mistakes committed by managers in employment?

Lack of clear communication.Misguided by some close people.Biasness

Mistakes  I believe  cannot  be  prioritized  as  as most  important or less important, contrary every mistakes  is important  because it  has  a  effect and  effect  has   ripple  effect.  Managers make  mistakes  every time  but  mistakes  inside  a business  domain are  termed as  bad decisions,  and  such  bad  decision  need  to sorted  out  by acting  or reacting. 

But decisions by management if based  on the  personal issues discrimation on sex  race  ethinic, can be  classified  as  highly unjustifed  ethical mistakes.

Not following the proper line of protocols during problem solving or any other issue.