FreeBSD after upgrade
===

I upgraded FreeBSD to new version and after upgrade many files in system have as owner set user 0 . 

Example : 

ls -l /usr/bin/su 

-r-sr-xr-x 1 0 wheel 16880 Jul 18 14 50 /usr/bin/su 

and is not possible to log as root to system only in single mode i can get in to system :/. 
also i can't remove or set S flag using chgrp (chmod also not work for files with S flag). 

Please for nay help. 

Best Regards 