Sharing & Permissions has 2 "everyone" entries, OS X 10.10.5
You can use Onyx - [freeware] to check/repair the disk, fix permissions &amp; reset ACLs.  

Maintenance tab > permissions, check the box at the top &amp; Execute.

Make sure you get the Yosemite version, they're OS specific.

This will default whatever it is you did to the permissions structure... which looks a bit complex to pick through manually.