And for Mac OS Sierra 10.12.5 users .
Go to users and groups , make sure allow user to administer this computer box is to be checked and uncheck allow user to reset password using Apple ID .
How to reset the admin password , if one has forgotten it .
Close all applications & shut down the computer , and plug the charger .
Press command + R + power key simultaneously , don't release the keys until apple logo appears , the bar will load slowly , let it be completed after a while you will enter in recovery mode .if you have enabled firmware password , turn it off .
Take your cursor on top menu bar & click on utilities > open terminal from here & type resetpassword the word is single & no space , all alphabets are small .Click on enter & close the terminal window .
On the screen you will see user name of the account , just select it ( press forcefully on it to get selected ) > click on next on the bottom side .
A rectangular bar appears > enter your password for Apple ID , a pop - up window will appear showing three options , continue login , create new keychain , update keychain password .Select continue login , And again go to top menu bar you will see apple logo > click on restart .
POP up appears on the desktop , enter in user library > keychains > remove alfa numeric folder to the trash , restart the computer and empty the trash .