Hello, this is my first post and I was hoping to get some help with a problem. Whenever I try and use the Sudo command I get the following error message: sudo: /etc/sudoers is owned by uid 503, should be 0 sudo: no valid sudoers sources found, quitting I have tried logging into single user mode and typing in the following commands: mount -uw chown /private/etc/sudoers 0 After typing in the chown ownership line, I get an error message saying “illegal username”. Different things I have tried: - Reinstalling the os (El Capitan) - Disabling System Integrity Protection (SIP). - Calling Apple Care who say that Sudo commands have been disabled in El Capitan. FYI When I run ls -la /private/etc/sudoers in Terminal, I get the following: -rw-r-----@ 1 MY-ADMIN-USERNAME staff 67 18 Feb 14:03 /private/etc/sudoers Note I’ve replaced my actual admin username with “MY-ADMIN-USERNAME” just so you know what’s showing. I need Sudo commands to work for a range of reasons, one of which is to get CrashPlan to work. Any advice would be greatly appreciated.