/usr/lib/vmware-vmdir/bin/vdcadmintool
Type 3 to reset and type the distinguished name of Administrator
account, In your case it will be cn=Administrator,cn=users,dc=vSphere,dc=local once you press
enter key, voila! It generates a new password and shows you on the screen.
Select Users and Groups, right click Administrator or there is an edit
user button on the top and change the password which you can remember easily.
Now log off from vmware web client and try with new password.