Since the release of OS X EL Capitan, Apple removed the option to repair file permissions as they do not need it because of the introduction of System Integrity Protection but there are some alternative ways to Repair permissions on macOS Sierra
Proper permissions are required for every file in macOS to function correctly, without chmod 755 & chown root:wheel Kexts will not work in macOS
For your reference:
chmod 755 (you allow everyone to read and execute the file, and the file owner is allowed to write to the file as well)
chown root:wheel (root is a superuser and wheel is a group of super users)
Before starting any process below, you must Disable System Integrity Protection, but if you have never disabled System Integrity Protection, then you do not need to repair permissions at all.
Here are some ways to repair permissions on macOS Sierra
RiparaCapo | Some ridiculous name
A simple app based on repair_packages command, which was removed on Sierra, but was available on OS X EL Capitan (read more: How to Repair Permissions on OS X EL Capitan)
You can Download RiparaCapo Application & repair-permissions by following on-screen instruction very easy.
alternatively, you can use the repair_packages binary package and repair permissions with the following commands
Open Terminal and type or copy paste the following commands after installing repair_packages binary (Permissions will be auto repaired when you install this package, so you do not need to rerun the following commands manually unless you need to)
To Verify your Disk
sudo repair_packages --verify --standard-pkgs /
To repair permissions