SharePoint Error : Configure managed accounts - object reference not set to an instance of an object

When I hit the configure managed accounts link in central admin all I get is the error:

Error

SharePoint 2010 configure managed accounts Object reference not set to an instance of an object.

The Reasons for this according to the cases i faced are :

1. Password mismatch between active directory and SharePoint ( You can use power shell command       Set-SPManagedAccount ) >>>>> powershell-script-to-change-managed-account-password
2. There seemed to be multiple entries for the same account , this was confirmed by running power shell command Get-SPManagedAccount (Please make sure that no multiple entries for the same account ,in case there is multiple entries try to remove one of theme using Power Shell command Remove-SPManagedAccount  >>>>  Item has already been added. Key in dictionary: 'domain\account' Key being added: 'domain\account'

Please drop me a comment if you found any new reason and i will update the Post accordingly.